Past 6 seasons - 12/13, 13/14, 14/15, 15/16, 16/17, 17/18 (this one). But yeah, 11/12 was a good one from Mourinho. He then went backwards in 12/13 and hasn't really been the same since. Also by saying he ultimately failed at Madrid, I meant in terms of the CL. Many Madrid fans blamed him for going out to Bayern, and with good reason, because he went pragmatic at a time when it was looking like they could hammer them and kill the tie. Also in 13/14... They finished 3rd, they were always around there, but it was pretty much always City and Liverpool looking favorites for the title. He played the role of spoiler and ending it for Liverpool more then anything.
And like I said in other posts, nobody can play great football all the time. I'm not saying we have to play great football all the time. It is important to always go with a game plan of trying to win the game though, which Mourinho definitely doesn't always do. It was always a criticism against him from many United fans before he came to United. And now that he's here, it's the same. Only now, he hasn't been successful. It's a point that many people have said. You get Mourinho to get instant success and win trophies. Not for the style of play, not to entertain fans, not to build for the future... But what happens when Mourinho doesn't get success? What do you have to defend him with? I don't see many signs on the pitch of him building a side that can turn into a top side in the near future. Many of our best players are constantly underperforming and we constantly play like a group of individuals rather then a sum greater then it's parts like Sir Alex always managed to do, and like how Pochettino, Klopp and Guardiola are all doing with their clubs this season. And at that point, why keep him?
The best thing about Mourinho's time here is that whoever takes over after him will inherit a much better squad then the one before Mourinho, so credit to him for that. But the players right now definitely aren't playing as good as they should be, and the majority of the time, Mourinho doesn't have us playing an entertaining style. It's not me glossing over other teams bad games and ignoring our good ones, you'd be very hard pressed to find people who would agree that Liverpool are not a more entertaining team then we are. Same with Spurs, and obviously City. Liverpool and Spurs are inconsistent, so it doesn't happen all the time, but they look on average more like a "team" rather then disjointed play that gets wins because of simply having better players like is often the case for us.