You are cherry picking stats to fit your opinion. Taysom has been shut down as many times as Tanner. UW, Utah, Wiscy, and Notre Dame to name a few.
I'll give you Michigan, but when your line is getting handled, your receivers can't get off the press, and RB's can't get though the hole, no QB will do well. We still lose that game with Taysom playing.
Tanner's struggles last season were not entirely his fault. He did not have the luxury of a good running game or a good offensive line. And he was thrown into the fire with very limited experience and preparation.