Others have piled on your post here, I don't mean to add to that but wanted to respond seeing as you replied to me.
I am purely ralking about on pitch attitude, I don't care for rumours and I definitely pay no attention to the press. When things aren't going His way on the pitch, he becomes sullen, insular, his head drops, he starts trying to force things on the ball and he's not good enough to do that which makes it spiral.
I get your point re a lack of confidence, but I think it's more than that.
I think the attitude issue goes right through the academy as I said - add to Rashford the likes of Pogba, Lingard, Greenwood, go back as far as Ravel if you want. We are bringing young lads through who think they've already made it, and lack the mentality to make the most of their ability. In my view, while it's easy to blame individual players, it's getting to the stage where it seems like the club is failing these young men somehow.
Out of every comment back, I will respond to yours as it's the most reasoned, well balanced and genuine response.
There was a moment, can't remember what game (maybe spurs?) Where Rashford could have gone for a 50/50 yet didn't even attempt it.
That was the first time I thought that something was up with the man.
But not once did I think it was an attitude issue. Moreso, a guy who has been thrust into political realms as well as thrust upon a pedestal at United, even more so after Greenwoods downfall, is struggling with this pressure and possibly depressed with the situation he finds himself in.
You make a good point regarding the youth products, and certainly Greenwood is a massive outlier. But Pogba has won the world cup and by all accounts is actually a hard worker on the training ground. Likewise Lingard, and likewise Rashford.
They are the new generation of players unfortunately, the likes of Grealish and Foden have done similar to our ex youth players for example.
Too much too young is a possibility, but also United are well known to have not looked after their youth prospects in a mental capacity in the past, this is changing now, big changes have happened at youth level and players are being supported more so this culture will be changing.