I think McCarthy is a good coach overall, but we needed to fire him when we did, given the disasters that were the 2017 and 2018 seasons. I never thought he was an awful coach as some did though.
I would also add that McCarthy is regularly criticized for only winning one Super Bowl with Rodgers, when other head coaches seem to evade the same kind of criticism. Yes, we would like to have won more than one with McCarthy, but can we take a step back for a moment and recognize how hard it is to win multiple Super Bowls? And how few coach-QB duos have managed to do it in the free agency era?
Shula-Marino 0 Super Bowls
Tomlin-Roethlisberger 1 Super Bowl
Payton-Brees 1 Super Bowl
Dungy-Manning 1 Super Bowl
Carroll-Wilson 1 Super Bowl
Reid-McNabb 0 Super Bowls
Levy-Kelly 0 Super Bowls
Reid-Mahomes 1 Super Bowl (so far)
Seifert-Young 1 Super Bowl
Holmgren-Favre 1 Super Bowl
With the exception of McNabb, all of those QBs are either in the hall of fame or will be in as soon as they are eligible. And I think it's fair to say that most football minds would rate all of those head coaches higher than McCarthy, even though many of them didn't have substantially more success on the field. For whatever reason, McCarthy gets intensely scrutinized for his failures with Rodgers, but people like Tomlin, Payton, etc., who also had hall of fame QBs, get off easy for the most part.
Yeah, maybe if we had a better head coach Rodgers would have won 2 Super Bowls, or perhaps 3 at most. But this idea that he would have won anywhere near as many as Brady, I just don't buy it. Brady basically broke it for everyone. He's set expectations so unrealistically high for everyone else. No one will ever do what he's done again. The only other coach-QB duos in the free agency era that have multiple rings are Shannahan-Elway and Coughlin-Manning and they each have 2. Brady having 6 with Belichick and 7 overall is a true anomaly.