I know you weren't talking to me, and i certainly understand why you feel that way... but I think he's a damn good coach who has a franchise that sunk everything into a QB that is killing the team. They have 3 #1's and a #2 invested in RG3-and-out, and he is playing absolutely horrible. It is very hard to win when your QB can't hardly complete a pass. And it won't get easier when another team is getting all of your high number 1 picks that Griffin is helping them earn.
Last year, it was Shanahan's coaching (and a string of good luck) that got them into the playoffs. It was brilliant running that offense with Griffin. Teams weren't prepared for it and Griffin didn't have to read defenses. Just smoke screens, runs to Morris, Griffin keeping the ball or throw to a wide open WR.
Teams were so scared about Morris or Griffin running they had to way over-commit to stop it. So when it actually was a pass, then Griffin usually had one read and it typically was wide open. If it wasn't, then he just pulled it down and scrambled for yards. Simple and effective when teams hadn't prepared much for it. It worked damn well when Morris and Griffin were running so well..
Now, defenses are ready for it, and the run lanes aren't there... and Griffin is having to actually play QB. He has real trouble reading defenses past his first option and his accuracy has never been good (contrary to what everyone was saying last season), so he simply isn't completing many passes. (and yes, last year I was saying RG3 was winning because teams weren't ready for that offense, that his accuracy was over rated, and that the only thing good about him was his running ability.)
It is very difficult for Shanahan to win many games when your QB isn't accurate, can't really read the defense, and your defense can't stop anyone.