Bill Belichick Will Likely Never Coach Again
The issue for Bill is that he needs too much control. He earned that status in New England and now that he’s moved on, he can’t go back to just being a coach.
Most GMs would be strongly opposed to bringing Bill in because it would likely mean their days were numbered. So if the GM is tight with an owner - that GM is likely going to advocate against Bill B.
Also, most owners recognize that you can’t commit the time needed for a guy like Belechick to come in and change the culture. You do better to hire young guys that can better relate to todays players and if it doesn’t work, you move on after 2-3 years.
Bill missed his shot to get out similarly to what Payton did when Brees retired.
One of BB's other mistakes was perhaps staying too long and believing that due to his incredible, unbelievable achievements in NE, he was "owed" by the Krafts, Patriots FO to allow him to remain as long as he wanted or needed to break Shula's all-time wins record. And we both know, House, that despite this gentle, nice, friendly "grandpa act" facade, Robert Kraft didnt reach the heights of business/corporate success and especially as it relates to being Patriots owner by being nice, conciliatory, and not making a sheet load of enemies. He's amassed a large share of enemies all over the Boston-area, all over New England, and within the NFL owners ranks by being a ruthless power player and wheeler-dealer.
He's been an outstanding owner, but there's been more then a few people he's had to step over, figuratively speaking, along the way and make some promises he knew at the time he wouldn't or couldn't keep throughout his life.
Also, even if Bill had left New England after lets say, the 2021 season in a similar manner to how Payton did, it still would be met with some criticism, or cynicism from sectors in Patriots fan base and the NE regional sports media community. Maybe not as caustic, or as critical with the same intensity with how fans here on SR.com claiming that Sean "quit" and lets be honest, he kind of did and he left the team's roster pretty bare afterwards for his successor. Those who claim Sean would still be Saints HC if we'd drafted Mahomes like he wanted and hes gradually inserted as starting QB by 2018-19, are probably right. Sean left because he knew he wouldn't win like he used to when Brees' was here for 16 seasons and didnt want to be part of any long rebuild.