No, that new corner restaurant going in downtown probably isn't going to threaten Applebee's... but... so?
And it doesn't needs to beat the X360 or any big consoles, but if it doesn't makes enough money to at least cover the expenses of the company behind it then what?
Yes. Your repeated key point -- wow, that's kinda vacuous and tautological. Basically you're saying, "What if you die, then what?" Well, you're dead. Duh.
Ouya the company could be run very cleverly with very low expense. It could be an unkillable cockroach in the way that a lot of bootstrapped startups are.
If run by employees who have day jobs, with open source hardware, it could have nearly zero expense for long periods of time. They could find corporate sponsors who could give them server resources for their marketplace, then it would be zero expense if they wanted.
The company could die and the Ouya community could still go on, so long as someone paid for the servers.