I'm not a fan of keeping someone because there might not be a replacement others like. I think Bill OBrien from Penn st. Would work and same with Shaw at Stanford. OBrien has NFL experience. I also think there are plenty of candidates in the NFL who could do a better job than what we are getting now.
I'm not exactly a fan of it either.
But, we can see some talent development under Garrett (Murray, Dez, Tyron, Leary, Frederick, Free, Harris, Hatcher, Lee, etc) and you can chalk up some of the issues to injuries.
I would just rather have that and try it for another year than try and rely on some college coach that is all the rave, but can't translate to the pro game. O'Brien would be a good choice though. I'm skeptical of any college coach w/o pro credentials unless he is truly revolutionizing the way the game is played. Jimmy didn't have pro credentials, but he created a small, fast defense and had plenty of sound theories that were well ahead of its time. While I'm not exactly sold on Chip Kelly, he comes across very similar. Otherwise you get another Greg Schiano.
YR