Because they happened at the end of the year. Beating 4 Mac teams, Rutgers and Illinois doesn't move the needle much. Again its about the recent record. 10-9 in his last 19 games. No Michigan fan cares that he started a season with 10 wins and then got bombed back to back to end the season. Michigan plays O$U the last week of the season, that game means more than all the rest combined, and getting bombed in bowl games doesn't help cleanse the palate.
There is not much of a chance to finish this season with a winning record so that puts him below .500. This isn't about what he did at Stanford or what he did in San Fran, I am grateful that he brought some stability to the program and took UofM out of the DickRod/cHoke doldrums but he isn't the coach he was when he got to UofM, you can see that not only in the record, but just the way he behaves on the sidelines. If he showed half the passion he once did I would be happy to keep him, but 5 false starts in the first half of the game. The refs throwing flags on every deep ball against Michigan and when Michigan WR get pulled down and tackled, he doesn't get pissed just stands there with a dumb look on his face.