The majority of this post isn't my work. The majority of this examination was performed by Yuni_Hermit (/u/Yuniwuff), and the full text of the post is on the Warframe Forum here.

The basic gist of it is, due to the slow nature of text chat during a time-sensitive event (such as Incursions or Bounties), communication tends to fall by the wayside. You end up depending on the other players implicitly, expecting them to do their job.

Enter the Convergence Orb, which tends to spawn outside of a mission area. The Orb, being an incredibly time-limited boost to an otherwise slow Focus grind, will most certainly grab the attention of every player, drawing them away from the mission at hand to grab it (akin to your phone ringing and you excusing yourself to answer it). Without communication (as noted above) players each individually rush off to their own Orbs, causing all players to abandon the current objective, and thereby causing the objective to fail due to leaving the area.

The above-linked forum post indicates one possible solution: instead of having the Orb be a pickup, have it instead be a consumable piece of gear (like health restores, pads, air support) that can be crafted and used.

TL;DR:

Convergence Orb spawns cause public-matchmaking (PUBG) team-mates to frequently abandon Bounty and Incursion objectives to collect said Convergence Orb and increase focus gains. This makes missions fail because of greed/need to grind.