While driving a coast-to-coast in a Semi; you have all the time you'd like to really ponder things. Easily my greatest thought (aside from Hot Pockets and Pop Tarts joining forces to make the COMPLETE dining experience) is the thought that in actuality - Mortal Kombat: Annihilation is the greatest Meta-Movie ever made; Johnny Cage's debut into film-making where he creates Earth-Realm's greatest Action-Epic to NOT ONLY cement his career as the greatest fighter ever, but as an act of charity of save the Shaolin People.

In order to prove this theory, we need to look closely at the specifics given in the first Mortal Kombat movie (MK1).

In MK1, the greatest fighters from Earth-Realm gather via the manipulation/suggestion of Shang Tsung and Raiden. After arriving and witnessing some pretty bitchin' Kumite, it is certain that should a warrior be defeated, Shang Tsung will absorb their souls (if they are not killed during battle), meaning that no losers will survive. Absorbing these souls will ensure that SHOULD Shang Tsung's forces be stymied and Shao Kahn be disallowed to enter Earth-Realm, Shang Tsung will be powerful enough to lead a campaign in his stead (or perhaps for his own benefit; dat sneeky snek). Ultimately, Earth-Realm defeats Tsung's forces and Liu Kang kills Shang Tsung in Mortal Kombat. As the tournament ends and Earth-Realm celebrates the assured peace for at least 10 generations, they are interrupted by none other than Shao Kahn himself who, in the movie's ending sequence, uses his magic to appear within Earth-Realm (at least as a projection) and threatens an invasion while destroying the Shaolin Temple. Raiden retorts with his catchphrase "I don't think so" as the heroes ostensibly attack Shao Kahn's party.

What we factually know from MK1:
1. Mortal Kombat is a generational tournament which was created to promote a (relative to war) peaceful aquisition of territories between Realms. It has specific governing bodies, the Elder Gods, who hold ultimate authority and power over the Realms themselves; which of course gives them the right to sanction the tournament as well as prevents any cheeky totalitarian from attempting to undermine the tournament's purpose.
2. Shao Kahn has had representation in the tournament and thus far has won 9 of the required 10 consecutive tournaments. For 9 generations (we could chalk that up to roughly 270 years, assuming a "generation" is every 30 years. Point being, a long ass time.)
3. Prince Goro is Shao Kahn's Champion; having been undefeated for 500 years. This means that either Goro is the keystone to the 9/10 victories, or he's been just an ass-kicker and valued member of #TEAMKAHN. Either way, this guy's been pushing people's shit in since before The Reformation of the Church of England.
4. Sonya Blade is a Military Officer who hunts down (and eventually kills) Mob-Boss Kano as vengeance for killing her partner.
5. Major Jax Briggs is decidedly un-robotic; as well as unsucessful in stopping Sonya Blade from pursuing Kano onto the ship sailing for Mortal Kombat.
6. Johnny Cage is currently in a production when he drops out, looking for a legitimate fight. He kills Goro.
7. Reptile gets kicked so hard he devolves into roaches; which Liu Kang stomps.
8. Scorpion is given a literal "Death Note" by Johnny Cage.
9. Sub-Zero is skewered like the "Petite" section on Brazzers.
10. Kano wastes a perfectly good turkey leg, making him the biggest POS in all of Earth-Realm.

OK, so these facts along with the story of the film and some deduction, I think we can make our case;

Unfulfilled as an actor, Johnny Cage enters the MK tournament. Witnessing the gravity of the tournament, including the death of his friend, Art, Johnny chooses to challenge Goro as an attempt to shore up the odds of victory; not because he genuinely thinks he can win, but IF he were to win, Goro would no longer be rag-dolling fighters and racking up an Ultra-Kill. Effectively, Johnny is attempting to save people's lives who're not going to be determining the tournament anyway. After defeating Goro, Johnny's sated with blood-sport and no longer wishes to fight; he would fight to help others, but no longer will he fight for his entertainment.
After the tournament ends, Shao Kahn attempts to attack Earth-Realm - directly disobeying the Elder Gods. Just as Raiden is powerless in Outworld, Shao Kahn is powerless in Earth-Realm and therefor projects himself magically to destroy the Shaolin Temple and embolden the troops he assumably sent. Raiden, Earth's Warriors, and The Shaolin defeat this advance and Shao Kahn is once again stopped. With Shao Kahn breaking the rules, it is assumed that the Elder Gods would strip Shao Kahn of his rights and De-Throne the Kahn. However, nothing happens. Raiden, confused, ventures to meet the Elder Gods and plead his case. Shao Kahn, likewise, is summoned to plead his case; the case being that RAIDEN invaded Outworld. Kahn's case would be as follows:
When Sheng Tsung kidnapped Sonya, he took her to Outworld - effectively removing her from the tournament. Sheng Tsung, being the emissary of Kahn (NOT the Champion; Goro was that), Sheng Tsung was not a legal participant in Mortal Kombat. In the same respect that Raiden was not a legal participant in Mortal Kombat; both parties were representatives of their Realms while the tournament was being held in Earth-Realm, not Outworld (which one can assume has hosted previous tournaments). Taken directly from the movie script is this dialogue between Liu Kang and Raiden:
" - And Shang Tsung. - Will he fight in the tournament?

lf he chooses to.

As a former champion he has the right to do so.

And he's far more dangerous than Goro."
The kidnapping of Sonya Blade did not interfere with the tournament, as Sonya had already participated and won her official fight; the fight with Kano. Final Mortal Kombat had not yet been bracketed, as the official win/loss between Goro and Johnny Cage had not yet been officially reported to both representatives (Shang Tsung and Raiden). However, the final fight had been determined; Shang Tsung used his right to challenge Sonya Blade in Outworld. As Shang Tsung fled the scene with Sonya, Raiden told Liu Kang and Johnny Cage the last rule of Mortal Kombat; "If she refuses, there will be no Final Kombat".
Due to the verbage of this rule, it's quite clear that the final fight would be a "no contest" and not a victory for Shang Tsung. Sonya's refusal therefor means that all of Outworld's Champions are defeated, with one No Contest. Earth-Realm wins. The moment Sonya Refused; The Mortal Kombat Tournament had been decided and since Liu Kang and Johnny Cage were brought to Outworld by Raiden (who could not travel there, supposedly), both Liu Kang and Johnny Cage were representatives of Earth-Realm's emmisary. The refusal of Mortal Kombat by Sonya had therefor been officially reported to both parties (Sheng-Tsung representing Outworld and Liu/Johnny representing Earth-Realm) as a victory for Earth-Realm and no other Mortal Kombat is to take place.
Aaaaand then Lui Kang challenges Shang Tsung to Mortal Kombat. This directly undermines the purpose of The MK Tournament; Lui Kang may have been free from the issue had he not killed Shang Tsung, but in doing so he cemented the affair as an unsanctioned match outside of tournament play - furthermore; he had killed Reptile in Outworld who was not only not a participant in Mortal Kombat, but a citizen of Outworld and within Outworld which makes a strong case that Liu Kang and Johnny Cage were in fact an invasion party directly endorsed by Raiden.

So, back on Earth-Realm. The Shaolin Temple is destroyed, Johnny Cage no longer wishes to fight, and an issue of Tournament Legality is being debated between Shao Kahn and Raiden in the God's Realm. Sonya has to return to her post, but Liu Kang is a near-broke man whose past has been literally obliterated; not to mention he might be Earth's greatest moron. What do they do?

Well, Johnny has to find an outlet for himself creatively since Martial-Arts participation is a bit soured. He's just been involved in the most ridiculous shit he's ever seen. So, he chooses to make a film about it; which is perfect - he has the basic story, he has the names and characters, he has a compitent martial-artist whose down on his luck right next to him (Liu), and he has a shit-load of extras who all have martial-arts experience (the Shaolin). After suggesting the movie as a way of funding the reconstruction of the temple, the Shaolin jump on the train. Naturally, Raiden isn't around - so Johnny gets a B-list actor to play the part, along with the part of Sonya (whom he takes the opportunity to sexualize due to his attraction to the real Sonya), Sub-Zero, Scorpion, and Everybody else he can either make up or actualize from reality. He even gets a body-double to play himself, which he kills off early to avoid any "actor-director" stygma. He even gets Bryan Thompson (Kahn), a B-list titan, to be in his film, undoubtedly due to the two more than likely having starred together in action movies before and a great person to cast as hype for the film (if Johnny was so famous, Thompson would probably be A-list in this reality too.)
Any of the ridiculousness of MK:A could easily be chalked up to the new-wave of CGI and Johnny's excitement to bring a real pizazz to the screen in an attempt to recreate some of the events he witnessed - along with many of the stories The Shaolin would have told him (things about Sindel, Animalities, ect.) This also explains why Jax is so drastically different between films; Johnny didn't really know him - so he made up a guy and named him Jax with the vague background that he's Sonya's parter - that's as much as Sonya had told him. Artistic license aside, the movie does glaze over major talking points of the games, which is exactly what an outsider to the lore would do; Johnny would try to cram as much as he could, but thousands of years of history is alot to put into one movie. Even the silly parts, like the underground globe-tram can be explained by choices Johnny made in his casting. When Johnny casted Deron McBee to play "Motaro" (his reimagining of Goro - as he wouldn't want to directly put Goro in out of respect for his dead friend, Art) Deron McBee would have suggested the tram-system to Johnny in a creative meeting: Deron McBee played "Malibu" from American Gladiators and it's no coincidence that the subterrainian globe-tram is just a tad gladitorial. As a slight against Goro directly, he added Shiva and unceremoniously had her killed in the film. The more you think about it, the more it makes sense that MK:A was a film directed by a newbie-director with major influences from martial-arts and the story being an attempt to retell lived-in events along with explanations from a secondary source.

At the end of it all, Johnny found a new meaning to Martial-Arts and the opportunity to help people around him with his skillset; fighting and acting. Plus he needed a way to pay for a new set of sunglasses.

TL;DR - Johnny Cage directed MK:A after the events of MK as a way of getting out of fighting and an opportunity for the Shaolin to pay for their temple to be rebuilt. MK:A was an "inspired by true events" film within the MK reality.