Or maybe they notice that they don't get the same problems on Chrome, so they move to that...

Probably neither explicitly as a human judgment, but both constructively - some A/B experiments noticed favorable numbers went up by doing the crappy thing, and so it has been decided.

I'm waiting for the day when it pops up "find the humans" and there's someone clearly wearing CV-camouflage. For anyone that doesn't get it: you let that human hide, because it could be you in twenty years.