I'm not a Rex fan by any measure, and had been saying that he shouldn't be fired after this season because that's just what a horribly run franchise does...keeps changing the coach every couple/few years and wondering why they still suck. Rex is the epitome of a players' coach, and he always takes the heat when things aren't going well, not sure he ever deflects the blame to anyone.
Having said that, his decision to punt on 4th and 2 in OT on Saturday, when ONLY a win helped keep their slim chances alive, and his defiance toward the criticism by saying "every coach in America would have done the same thing there," coupled with his defense getting gashed on the ground again (and just being pretty much horrible all year and last year), was the final straw and I can understand why he was fired. Still don't necessarily agree with it, but I can easily see why. Rex is just stuck back about a decade ago with his coaching philosophies and decisions. Now all he needs is a good common sense coach (how have we STILL not seen one of these coaches brought on board) and he would have been fine as they would handle when to punt, when to kick a FG, handling of the clock and timeouts, challenges, etc.
How Doug Whaley still has a job as the GM is the more important question. Outside of him being black, and the Bills liking that look, Inhabe no idea how this guy is still a GM. Not to mention, if you're going to keep tweaking things every couple/few years, at some point you HAVE to clean house and start anew.