A lot of small tubes have died out, with webmasters thinking a tube is quick and easy money!
The big tubes get a big percentage of the tube traffic, and I am sure all these accept submissions, even if they are the enemy of most webmasters!
There are a lot of Successful smaller tubes (I mean smaller than the mindgeek crew) out there, trick is finding the ones that accept submissions… a lot of them are just clone type sites that auto populate with bigger tubes content…
I am sure there are a few tube owners on here who will post here after me, and I am sure they would love the opportunity to host your videos!