There's also a lot of people who saw him demonstrate immature behavior. In the Notre Dame game he was yelling at his teammates
These criticisms are such nonsense. Tom Brady would throw hissy fits on the sideline all the time. He'd yell at players, break tablets, etc. Aaron Rodgers is famous for shitbag behavior too. Players get emotional on the sidelines all the fucking time. Just ask yourself why Williams is getting so much hate, but this behavior is excused for other players.
Also, you are making shit up about lower ceiling/lower floor of Fields. This is quite literally the opposite.
You are scouting box scores. By your logic, Fields has a higher floor/ceiling than Mahomes, Allen, Herbert, Luck, and the many other elite QBs that have never been to a national championship.