I'm not saying that most coaches should keep their jobs after six seasons like Garrett has had (though I also don't view the 8-8s as harshly as you probably do because I think we legitimately had a bad team in 2011, 2012). I'm saying you have to look at each case and see if the problem lies with the coaching or somewhere else. In our case, I think we grew through some early coaching issues (gamedays and in assembling the staff, as I said), but by and large, we've had personnel issues on defense (on top of the OL problems early) and we've had a meddling owner who's made things difficult. Despite that, we've actually been fairly competitive during this run and not the dumpster fire many would like to misremember.
I never suggested I thought Garrett was an average coach. Maybe you place more value on the things I criticize him for than I do, but I don't think he's just an average coach when it comes to the Dallas Cowboys.
And, newsflash. It's personnel more often than not that keeps teams from winning the playoff games in this league. There are a lot of good coaches, but great players are at a huge premium. That's the way it's always been and the way it's probably always going to be. We haven't had an elite roster overall, and I don't expect the coaching staff to close that particular gap.