This is the truth. That line, even at it's best this season, was one of the most inept O lines I've seen at this level. Going back to your first sentence, the people who hate the coaches will say (with some degree of validity) that it's the coach's responsibility to ensure we have capable players and that they're well-coached. People who give the coaches the benefit of the doubt will say "yeah, but we had some unexpected attrition there".
The answer, as usual, lies somewhere in the middle. What really worries me are two things: First, the line didn't improve much as the season progressed. If they were green to start, you'd think they'd solidify as we got later into the season. B (to quote Buzz from Home Alone), the problems looked like the type of problems that should be easy to rectify. It wasn't that they were getting out muscled, most of the time it just looked like they didn't know who to block. That, to me, indicates either that they're dumber than a box of rocks or the coach isn't successfully teaching them what to do.
What really has me confused is that KF was uber complimentary of Barnett mid-season...really gushing over what a great coach he is. Was that an attempt to deflect criticism or do we have a "great coach" who, for some reason, can't teach a handful of college kids their blocking assignments and techniques to deal with the stunts/moves DL were using against us?
It's gonna be really interesting to see how this off-season and next fall play out. When KF named BF OC, I really expected Kirk to pull out all the stops to give him the "tools" to be successful. I thought he'd look for JUCO players, emphasize offensive recruiting, etc to ensure BF's success. Yet, to the contrary, he seems to have done the exact opposite. It's really a head-scratcher.