I agree that a coach needs to adapt style to the individual to maximize what they get out of them.
I see McVay as being much more stressed the last 2 years. The first 2 years most things were working and he was excited to be a HC. Then the Super Bowl happened and he probably felt embarrassed.
After he went away to Costa Rica? and had some time to chill a bit with his wife, he came back very much more calm and controlled and was very nice about Goff again.
In my view he has his toughest season yet from an expectations perspective. No one expected anything in 2017. Now he's made a ton of moves, had a lot of coaching staff turnover. Traded QBs to win a Super Bowl now.
We all get more stressed under pressure and tend to lose our patience. We all handle it differently.
McVay shouldn't shy away from holding players accountable, even publicly if they need it. What I saw was McVay losing control of himself a bit and get it back once the season was over.