I think Bohn's a problem, but he's the least of our problems. If we had an acceptable President and Chancellor along with an acceptable football coach, I'd direct my anger at Bohn. I want a dynamic leader and visionary in the position. That's not Bohn.
But Bohn is well-trained in the role of AD, cares very deeply about what he's doing, is very responsive to his coaches, and is always working hard to improve things. He's a good soldier. With the right coach in place, you can win with an AD like Bohn. With a supportive administration, you can get a ton of support infrastructure done with an AD like Bohn.
Right now, anger directed at Bohn is a sign of fan desperation. It's that glimmer of hope that if we had a "take no prisoners" type (i.e., a Bill Parcells personality) that our AD would force the issue and get all the things we need despite the administration. In reality, the people at the top determine what's possible. To use a pro sports analogy, if you've got an owner like Donald Sterling of the Clippers who doesn't care about winning and just wants to milk it for as much profit as possible by taking advantage of all the investment other owners in the league make to improve the product & tv revenue... it doesn't really matter what the GM hired to manage the Clippers wants to do or what type of personality he has.
The Buffs are the Clippers of the Pac-12. Bruce and Phil are our Sterling.