I don't think I ever said he was the worst HC ever, I think he was below average and should've been fired after 2017 at the absolute latest, although 2012 or 2013 would've been perfectly justified as well.
It all ended up well enough with McCarthy, but nobody knows what the opportunity cost actually is if we would've gotten rid of him in 2017, let alone 2012 or 2013. I'm never going to defend Garrett just because he managed to take some extremely talented rosters and put up a Wade Phillips-esque resume over a decade.
But I'm not "defending" against anything you said verbatim in that post above. I have no issue with you saying any of that - even if I'm saying I wouldn't have PERSONALLY fired him after 2012 or 2013 absent someone like Reid (or, like a that-timeframe McCarthy) being brought in.
It's the down-the-rabbit-hole ridiculousness like trying to make every last thing a moratorium on the last administration's failures. Newsflash: He had a seat at the table for personnel decisions and they were on average pretty good decisions. That by itself was shown that it can get you a bounce or two away from a Championship game. This most recent trend of trying to say McCarthy is the one responsible for us nailing the draft, and that the last regime failed at the draft, is silly and is contradicted by the entire claim that the team was super talented and it was a Garrett failing that he didn't get enough out of the talent.
Everyone is in a race to find the Garrett bogeyman in everything. And the reason why a nuanced perspective is important, to get back to your other question, is so we can know who was good at what and where the ACTUAL failings are, so we can direct our angst to the RIGHT parties. If the coach is doing something right and other things wrong, at the end of the day he has to be accountable, no doubt, but at the same time, maybe the coach needs better support elsewhere so you can keep him for the things he IS doing well.... or so that you don't make the same mistakes with the next coach, who also deserves a fair shake.
McCarthy has been a top 10 coach in this league and I have all the hope in the world for him, but he also got stale in Green Bay. If he doesn't instantly come in and improve us dramatically there will be questions abounding. But maybe those questions don't need to involve throwing McCarthy out with the bathwater but instead revolve around questioning who is doing the player selection, who is interfering with practices, or who he's been asked to consider for assistant coaching positions on either side of the ball.
I will also reiterate another point no one ever wants to consider: What we want is of no consequence, what Jerry wants and will do is what is important. And "suffering" through not firing Garrett after, say, 2015, means we had to "suffer" a pretty exciting year and a divisional round playoff appearance in 2016 and through an exciting playoff win and a divisional round playoff appearance in 2018, finally culminating in a coach we all feel great about in Mike McCarthy being hired for 2020, with hopes that he could be here 10 years and win a Super Bowl. He's that caliber of coach.
Here's the coaches hired in 2015: Adam Gase (fired), Ben McAdoo (fired), Chip Kelly (fired), Mike Mularkey (fired), Hue Jackson (fired), Dirk Koetter (fired), and Doug Pederson (Super Bowl winner).
Given that we were not gonna be hiring Pederson as he was a Reid disciple bound for Philadelphia on that pipeline (and I'm frankly not convinced he's that good anyway), the question is not a matter of "Are any of these fired coaches better than Garrett?" (which I'd argue essentially NO), it's, was it worth suffering through Jason Garrett to get Mike McCarthy in 2020 instead of these assholes? You hire a guy like that in 2015 or 2017 and it's very possible that McCarthy is not your head coach right now. This was ALWAYS the point behind the targeted upgrade approach.