I'm not really going to look at the defense and hold that against Garrett or anyone else. You can scream coach failure all you want but you can't be scrubs on the field and compete with good teams. If you want to fire someone over the defense then look at Jerry. His cap problems, poor trades, and until recently bad drafts have put this franchise at 143/139 since the 1996 season.
I'll say this in Garrett's favor. Since his arrival the arrow has pointed up. Some are sick of this most likely but you can't really evaluate the job Garrett has done overall the last two years due to the decimation of the defense.
Now what bother's me is the penalties (which to be fair have gone on for almost two decades), mistakes, at times poor time management and HCing decisions, and lately the performance of the players esp the OL. I know Bernie has screwed up the chemistry and he looked horrible in what I say of the NOs game. But Witten and all were blocking the wrong guys at times. They were trying to run the ball with 9 guys in the box. Now it takes guts to run at nine but if you get thru the LOS you can break that in a hurry. But if you're blocking that poorly (and guys in the box should see that and let Garrett know) then you must throw the ball. Another thing that bears more inspection (too small a sample size) but once again the other team seems to know when it's a run or pass. That is a monstrous red flag if it is true which to an untrained eye may be the case. But we heard and read a lot about being predictable. This is the first I've said of this with even uncertain conviction.
I'm not smart enough to know what all the problems are and I would give anyone a pass on the defense the last two years. But I can't forgive persistent problems on the offense. Now to be fair, we were scoring almost 30 a game until very recently. But if you look at the team's offense since the end of 2007 you'll see an offense that is failing to score enough points.