I think that the whole thing runs deeper than that. It starts with Moyes. Inept as he was, deserved sacking as it was, it was still the first player power thing that got him fired alongside his obvious shrotcomings and ineptitude. Nonetheless, it was the first sign to the players that 'if you want to sack the manager, you can do it', something that obviously was not present at the club for the previous 26 years. After Moyes was gone, plenty of players have gone public with criticism of him, generally speaking the blame could've been and has been laid on Moyes. Everybody else was absolved of the responsibility. Players came and went, new managers popped up, so the first year under LVG we've done okay-ish - we've gotten ourselves 4th, it was better than the Moyes disaster. Meanwhile we've had some questionable transfers done, Rooney's contract extended, lots of talk about 'signing a galactico', so we've gotten di Maria who never really wanted to come here, crock Falcao, past it Schweinsteiger.
So after some time, even though our players were in awe of LVG's professionalism and honesty at first, those things became a problem. Being recorded and then analysed at Carrington became a problem. Our players were sent their performances analyses that they didn't even bother to watch because LVG's a dinosaur and how can he even question them. He was blunt with them, but honesty is only good when you're saying honest nice things about people, when shit goes sideways and it's criticism, honesty is good no more. So they got him sacked, we've won the FA so all the glory to the players but LVG goes. Situation is repeated, players go to the public, talk shit about the manager, general consensus is that it was LVG who's just way past it and new manager will get us going. Everybody else is absolved of the responsibility again.
Mou comes in. We take him in with all the baggage that he brings, the good and the bad. He knows that people like Schweinsteiger shouldn't be here so he tries to get rid of him but we then have got Bayern, half the media and big chunk of our fanbase berate Mourinho for behaving like he did with Scheweinsteiger, even though the problem was brought upon us by Woodward and LVG, he has to deal with this shit. We've still got way past it Rooney, again, problem brought upon us by Moyes and Woodward. He finally gets rid of him, so it's a problem less. But the players still know that there's this button that they can activate that deals with the problems once they are simply bored of the manager. We've got Zlatan in, apparently he's the problem for other players because he's slowing down the play and shit. We've got Pogba who always wanted to come back here but actually wants to feck off after two or three seasons. Martial for whatever the reason is sulking, Pogba is sulking (to be fair everybody knew that sooner or later he'd do that and he wouldn't be the player for the next 10 years or so, don't know if anybody seriously ever even considered that), Raiola's dragging the club through mud but it's not really a problem for Pogba as he's getting him a new contract. Meanwhile we get Sanchez in, who seems to be nothing other than a bust for us and another Schweinsteiger case.
Now don't get me wrong, I'd be deluded to say that Mourinho holds no responsibility for this shit, he's done plenty wrong and it's obvious here. For me, there's probably no coming back for him now so he'll have to walk. But some of the shit, including horrible mentality that runs through the veins of this club ever since SAF departed, is not on him. Players have seen the corruption ever since the Moyes times, some of the players are still here (which begs a question how clown like Jones can still be here after so many years), the same players that got Moyes and then LVG sacked. It could've been Martial's first year at the club, it could've been LVG who's brought him in, but he's seen that if you try hard enough, you can feck off the manager if you no longer favour him. Which is being the case now. Again.
It's like with a teacher and students. If the teacher shows the students that he falters in disciplining them once, they'll know it for years to come and exploit any possiblity to take shit on him once they want to. Woodward, who plays the principal in this analogy, has come to the class, let the students take a shit on their previous teachers and prenteded that everything will be fine with a new teacher. So some of the students graduated, some new students joined the class, but the rot and corruption is still within the class because the principal has let it slide once. Now it's not really him calling the shots. It's the students, even if some of them come and go.
You also have to ask questions of our medical staff how over the years we're still getting players like Rojo or Bailly in, who are constantly injured and unreliable. We've got Smalling, Lindelof, Jones, Rojo and Bailly as centre backs, three different managers have gotten them in and only Smalling and Lindelof are not injury prone, you can ask plenty of questions of their quality too. Honestly, how?
Serious point though is now when Man,. United go 2 down in a match there is no belief they'll turn things around like the good old days.