I suspect that's sort-of right.
That they're still getting something out of the game, and at least internally, its a 50+1% thing where its more worth staying in, for whatever reason, than getting out.
But that doesn't mean they really, really don't like the thing(s) they're complaining about, its just there's a counterweight they're not discussing.
(I just pulled the plug on GMing for a certain group I'd done that for for a long time (and in fact GMing at all at least for a few months), and I probably should have done it a fair while ago, but I was still getting things out of it I didn't want to lose; I just finally concluded that 50+1 wasn't there anymore).