In the short term, yes - but in the long term we'll probably find a new balancing point between the big budget pro shoots and the amateur ones. Maybe some of the big studios will crash and devolve into making cash-grab type short films, maybe there'll be more and more amateur shoots with better quality production. Either way, market's gonna expand.
As for "for-fun" vs "for-profit".... Yes, but also, if someone's posting for fun and there's opportunity to make extra money out of it, then no reason why they shouldn't take it. Not like we can tell who started off doing it for fun and who did it for the money. The ones who keep spamming their OF links everywhere are a problem, though.