I disagree somewhat - well, I think simply backing up content is insufficient but if you diversify your platform now and manage to snag a significant number of viewers then you should be good. Shared platforms like DLive (a la pewdiepie fame and others) or watchnebula.com is one way to do this and can be very strong for topically related subjects - independent platforms like Dropout.tv are also an option but you're either hoping to win the bandwidth vs. advertiser cost balance or going to need to charge for access - both of which can lower your subscriber rate.

I think it's hard to make a fully independent platform so I think topical ones are a better option - but YouTube is really in a position of power due to the network effect. As long as they don't shoot themselves in the foot with controversy and banning then they should be able to easily hold onto their position - everything challenging them has an uphill battle.