There's this kind of sarcastic self-aware quality to the writing that I was never entirely sold on.
That's another thing that turned me off about FF or any other Whedonverse show. I don't like how his characters are all smartasses. I can't stand characters like that. I never did care much for Han Solo in SW - I always thought he was an unlikable jerk. So I'm sure that colored my opinion about FF.
Plus, in general, I don't want my sci-fi to be about rebels. I never have liked characters like that. SW gets a free pass on this, though, because the Empire clearly deserved to be rebelled against. Not so with this (the Alliance is not the Empire - not even close). I cannot like, or sympathize with, the characters on this show. I would not be "on their side", I think. I find rebels to be boring to watch. I like my shows to be like Trek - true heroes who are out to explore the galaxy. Not just a bunch of losers in a junkheap.