I've been an "in Bill we trust" disciple (mostly, not hardcore) for years.
I think the fire and skill level of Bill has eroded. Brady's hasn't.
I don't see how this is so complicated.
Belichick does some things extremely well, many of them actually. He's done pretty well in most trades. He does a good job in UDFA. Like the Ravens, he's got a system down for getting compensation picks. He manages to make trades that bring in volume of draft picks, he can split a quarter into 4 dimes, 2 nickels and 6 pennies. His late game management is very good. His Special Teams units, his personal bread and butter, usually are very productive.
But he's generally a lousy drafter. Sure he's hit on picks, but he's had a ton of them. You can argue with his unparalleled job security, that he's made more picks at his own discretion in the last 20 years than any other personnel decision maker in the NFL period.
If Belichick was a better drafter, Brady would still be a Patriot. There would be a constant reload of new cost controlled talent to help the team win and maintain depth to curb the impact of nominal injury attrition.
One could also argue his flavor of the Perkins-Erdhardt offense was much like Phil Jackson's Triangle Offense, it was versatile but too complicated for the reality of the abilities of most of the general NFL talent pool.
You could argue the Patriots might have been better off in the last 20 years just trading their draft picks. They would have gotten a better return on players who could contribute. Yes, there was some really nice picks in that mix, but the overall results across the entire Belichick drafting history is pretty ugly.
What makes me happiest is that, in the end, Joe Montana loses. Montana was one of the greatest QB1s to ever play the game. But it's no secret that he's an arrogant diva and has always been that kind of guy who needed it to be all about him. That Montana lost the "Best QB1 To Ever Play The Game" title to Brady tends to please me to no end.
That being said, being in Tampa has given more media exposure to Brady and he's been more candid and while he clearly says the right things and shows leadership and he's a winner, his inner sociopath comes out more. It's well known he saw a sports psychologist at Michigan and while I think it's a good thing for the perception of general mental health in America, I have no doubt he found his personal Dr. Melfi and his inner "stone cold killer" came out.
Winners tend to be throat cutters. Just how it works.
If Belichick wanted a different narrative than this, he should have drafted better.