BCC seems very sustainable and stable as such. I think the only 2 reasons that it can collapse is either some kind of gov-t decision to shut them down or owners telling themselves "OK, I think I've got enough money now and can quit business...". And the 3rd reason being BTC collapse of course

I think owners will never will tell themselves that they've earned too much and now they must shut down the system
I find first reason the most realistic.
Also they have 14 founders, so maybe they may encounter some problems with sharing proceeds. Maybe there will be a fork in this case, who knows

The only thing I know for sure is that currently everything is totally fine.