I have heard on internet that people are disapointed about kairi's role on the last world of KH3 since she becomes the damisel in trouble once again on that level, well what i have to say is that as much as it sucked to have all that development that made us thought that kairi would be a good keyblade warrior being thrown to the trash, it makes sense to have kairi as the damisel in trouble since basically she had just become a keyblade warrior therefore it would make sense to have her being kidnapped since she wouldn't be able to defend herself against her kidnapper and if someone goes with "why then axel wasn't kidnapped as well?", it was because even without the keyblade training axel had skills, after all he was part of the Organization XIII, therefore it's basically logic that the kidnapper decided to kidnap kairi instead of axel.

so basically, even though it was disappointing to see kairi being kidnapped despite all her training, it makes sense since kairi wasn't that ready for a battle of THAT caliber