Why was Taylor benched in the first place anyway? Makes no sense whatsoever.
He played two crappy games, and people called for him to be benched is the short, easy answer.
The long answer is that 1) They wanted to see how good Peterman is, and whether or not they should draft a QB in the next draft, and whether he's the QB for the future and 2) They wanted to see if Tyrod is worth keeping, since if they keep him they'll have to pay him ~$20 mil, but we know he is not a $20 mil QB. If you analyze it, the move makes a ton of sense, but if you use common sense, the move is foolish and dumbfounding (typical Bills logic).
Now, expect the Bills to ditch Tyrod at the end of the season and try for one of the QBs expected to be free agents like Cousins, and draft a QB.
But the stats tell one story about Tyrod, but the eye test tells the other. On the stat sheet he is safe with the ball, gets 1-2 TDs a game and 150-250 yards. But when you watch the game, he's safe with the ball, but he doesn't take risks and when he does they're really bad risks. He extends the play by leaving the pocket and picking up yardage, but he never goes through his progressions (but does he really have the line to?). He's a QB good enough to take a great defense to the playoffs, but not good enough to carry a below-average offense. When that defense started to play like garbage in New York on Thursday night a few weeks ago, it didn't matter who was in that pocket unless it was Brady or Manning, they were going to lose that game and any other game the defense plays like that.
Don't be surprised if the only game they win from here is the Miami @ Buffalo game. New England's sweeping them, KC is going to beat them, Miami will probably beat them in Miami like usual, and the game against the Colts will probably be a complete embarrassment, and not for the Colts...