Literally every club cycles through managers until they find one that does well, it is just normal and nowhere near as dramatic as some of you like to act it is. You would have said the same about Ancelotti for any club, yet Leverkusen brought in Xabi Alonso and won the league title a few years later, same story at many clubs who progress under new stewardship. It is not a problem if a coach comes in, does a bad job and then is replaced...what IS a problem is when we act indecisively about his underperformance and have fans wanting us to make decisions based off of hope for miracles rather than logical sense. That is when it becomes toxic and tiring, while at other clubs they simply swiftly replace the guy who is not performing up to par and move one. Our fans make sacking a manager out to be like we are torturing the bloke, it is just a normal part of football just like selling players.
Sticking with what you KNOW does not work is literally the most illogical thing I can think of, especially if the reasons are just blind hope and this weird fatigued mentality of 'we can't keep doing this' when literally everyone else can and does. What are we supposed to do? Stick with a failing manager and just keep buying more and more players until hopefully the sheer talent on the pitch outweighs his poor instructions? What logical reason and actual benefit does sticking with a failing manager have? Fans don't have the same logic with players, if our keeper lets in 3 soft goals a game then there would be no hesitation to call for his head.
I don't blame some of our supporters because all a lot of us know is the comfort blanket of Fergie, so some find it hard to think normally about the club compared to their outlook on other clubs. United fans are basically like rich kids who never realised normal people have to go and get jobs to make money.