Does he?
Don't get me wrong - he certainly is underperforming with the players he has at his disposal, and does himself zero favours by singling his own players out in the press, but would they be able to compete with Liverpool or City even if these players were playing to the best of their ability?
Let's go through their first-team squad objectively.
De Gea is a world-class goalkeeper.
Valencia is inconsistent. Dalot is a kid. Young is a decent back-up, but is relied on far too often in the first 11.
Smalling isn't good enough for them. Rojo, Jones and Bailly always appear to be injured, but all of them don't seem to be particularly adored by United fans. Shaw is starting to come good after an injury-plagued couple of years. Lindelof is ok, but doesn't appear to have fulfilled the potential people thought he had at Benfica.
Fred hasn't been that impressive, but he didn't look all that impressive at Shakhtar, either. I think Mourinho even alluded to Fred not being a player that was one of his first choice options.
Fellaini is useless as a starter, albeit he's a good impact sub if you need a goal. He is relied on too much, though.
Mata is class. Matic isn't mobile or energetic enough for a two-man midfield pivot. Pogba has blown hot and cold, but don't think Mourinho has developed him properly. Lingard is average, who had a purple patch last season. Seems to have reverted to type this season. Herrera is technically gifted, but again, struggles for consistency.
Alexis Sanchez is half the player he was at Arsenal, but you could see signs he was on his way downhill in his last few months at Arsenal. Doesn't have that explosiveness or quality in the final third that he used to have.
Lukaku is a good striker, who is lacking in confidence right now. But again, question marks have always been around whether he's a top level striker. Rashford is also lacking in confidence, but is a good young player. Martial is quality, but has been inconsistent since Mourinho's arrival.
They have a top goalkeeper, a slightly above average defence, an imbalanced midfield and a wealth of attacking options.
Generally, I agree that he has mismanaged his players and alienated them. You can certainly argue that Mourinho's poor man management skills have contributed to their indifferent displays. But some of them, who were there previously, weren't putting in stellar performances under van Gaal either. At what point do you say 'the players aren't that good' instead of always looking at the manager(s)?
He's spent almost £400m since 2016, so he has to bear the brunt of the criticism he's getting, despite his protestations to the contrary.
But relative to the other squads, I personally don't think these players are good enough to win major honours. They should be doing better than they currently are though.
