Because they only take the hardass stuff and forget everything else. Bill changes his scheme to fit his talent, he's not trying to force anybody into a role they aren't suited for, or shit on them for not fitting his scheme, stuff like that. He's a flexible hardass when it comes to coaching.
Not to mention they forget the human element. Yes, Bill is a hardass, but you don't get players being willing to run through a brick wall for you just because of that. He's like a grumpy old grandfather. The one who's gonna bitch and moan, but helps you out with stuff as a kid. Meanwhile, Patricia and McDaniels (probably the most notable examples) are just pricks. They don't respect their guys. Belichick does.
Chiefs should have gone for a proven WR before the deadline. Can't rely on just Kelce anymore.