It's still about the bottom line. To their credit, they seemed to have taken the Firefly issue to heart, and stuck with a show like Arrested Development (perhaps the best network comedy ever, seriously) to their financial detriment. Fans still didn't support it enough to warrant the financial outlay, so Fox may think twice about keeping a great, but unprofitable show on life support in the future

We can all blame Fox's various decisions: i.e. airing episodes out of order, shifting around the schedule, etc. and they are valid to a significant degree. But the bottom line is that we, "the fans", did NOT support that show sufficiently to demonstrate its sustainability. The instant we heard that "hey the guy who did Buffy is doing a sci-fi western thingy", that should've been enough to flock us together to fuel the ratings.