No one is in business just to spin their wheels. Money talks and BS walks. The post rate will go down.
The big push to get users in here, at least from YouTube to DTube centers around freedom of speech. Same with FaceBook. However, the incentive of getting paid for your posts is also pushed, quite openly. I would say earning for your content tilts the scales lower the other two.
Most people come over here to "get their feet wet", so to speak and I think after the infatuation phase goes away and they see little to no ROI for their efforts, they simply abandon ship back to there their friends are. If one is little better than the other, and the other has your friends, where would you go?
Freedom of speech is great, but with no audience? You might as well not speak at all.
That said, minnows tend to find other minnows, so the future is not too bad. It all depends on how popular you get I suppose.