Don't know how much blame I can put on Stefanski. The reality is this teams roster is not good and will take a lot of time to get better.
Hindsight is 20/20 but Haslam almost certainly forced the Watson trade and signing and Berry is his yes man. That may go down to be the worst trade and contract in NFL history. Did Watson play terrible yesterday? No, but again he wasn't a difference maker at all. Part of the problem is he really has no weapons to work with, and the offensive line stinks. Injuries play a role there, but when you don't have early round picks, you suffer on depth, be that on the offensive line, receivers, or the linebacking core and secondary.
Watson isn't a leader either. It's painfully obvious that Copper does not want to play with this guy. Jeudy is OK, but again, you could've went out and drafted someone if you had the picks.
The only way to win in this league seems to be getting a good QB in the draft, having him be good almost immediately, and use his first 4-5 years to go and win on that first contract. Then when you resign him you need to go back and rebuild through the draft. Kansas City has mastered that.
Stefanski is ultimately the fall guy. But don't be surprised when the Eagles hire him and they turn it around. We for some reason believe this idea that this team has a good roster and they don't. Blaming the coach only gets us so far.