What I don't understand (speaking of Vimeo) is why doesn't YouTube offer a plan where individual content creators can choose to pay a monthly fee to keep ads off of their own videos for all viewers. Speaking for myself I would happily pay for that.
You can read the Vimeo thread for why it can not work. If people pay a monthly fee, and their views skyrocket, you either have to force them to pay much more, or to restrict their views somehow, both of which are just so so bad compared to the current scenario (this is exactly what Vimeo did).