The right answers to lots of the questions being posed here are actually quite simple, but to really get to them is in many ways complex.
To start with, you don't need to be an expert in medicine to hire a good surgeon for your hospital. Just like you don't need to be the world's brightest mathematician to hire a good mathematics professor for your univerity. A basic knowledge in both fields helps, of course, but a little is sufficient.
What you do need to have is the right criteria when selecting for the best candidates. Things like general intelligence, a good ability to explain their work in the field, a good ability to explain their values and why they work the way they work and why that is the best way to operate within that field. Additionally, things like a generally pleasant attitude is important. Especially important in roles where that person is some sort of team leader, since their attitude will have a great impact on the team they are leading.
Our hiring process has been lacking any of those things, as far as I can tell. Since Sir Alex we first had a Scottish guy who seems like a decent fellow overall, but whom it doesn't take more than 10 minutes of listening to, to figure out that he does not posses the intelligence or leadership qualities needed to lead a top football club, no offense to him, it's just the harsh truth.
Then we hired a man whose insistence on a specific football "philosophy" was extremely rigid, outdated, and overall uninspiring to the team and limiting to our progress in the long run. These things should have also been painfully obvious if anyone at the club spent some time seriously discussing football with LVG.
Finally we hired Mourinho. Not a lot of description needed for him but, it suffices to say, it should have also only taken a short conversation, or a short youtube search, to figure out he was never going to be a good fit, in the long run, to manage our club. Anything further than letting him take over some training sessions during the summer for variety's sake was him being in the job for too long.
What I'm trying to say is - there has been a lot of conversation about what types of things bring success. Is it being a 'real man'? Is it praying to the football gods? Is it playing a certain style of football? Is it playing Fellaini up top? Is it being bald (like recent history suggests)? Is it being charismatic? Is it being likable? Is it being a legend in the sport?
There is an answer to this question here which is, and has been, there for anyone who has seriously tried to figure it out. And the answer goes something like this: While it is not easy to predict what the best attributes that lead to success are, there is one that stands out and is possessed by the vast majority of successful people, particularly when it comes to management and leadership positions: intelligence.
Jose certainly believes that he is extremely intelligent but watching him contradict himself every other week should be proof that he is in fact supremely confused. Going even further, his renowned reputation as a manager who understands psychology to a high degree is completely laughable. He doesn't even seem to understand his own emotions most of the time, with plenty of examples to point to since the beginning of this season.
I obviously don't know Jose in his personal life but in his managerial career, especially since his second sacking from Chelsea, he has too often behaved like a textbook narcissist. And they all think that they are much smarter than they actually are, and they all refuse to change their stubborn ways, and they all point to anything and everything around them to justify it when they begin failing at whatever it is they are supposed to be doing. They will especially do this with things that are true.
That's the tough part for people to understand - a cunning narcissist, when failing, will not just begin blaming the weather or the fact that he woke up in the wrong side of the bed that morning. He will instead blame things that are actually kind of true, but blow them out of proportion just the right amount so that you feel like you are losing your mind. This is also called gaslighting. The desired reaction is - well he can't be wrong because what he is saying kind of makes sense - our players do kind of suck, the board does seem to have been doing a bad job at managing the club since SAF retired, City do seem to have spent a lot of money, Pogba does seem to post a lot on Instagram, Martial does seem to always have a resting b*tch face on.
Anyone can point to problems. The best leaders and managers, and more specifically the most intelligent people and the most successful people at most things, have never, as a general rule, been ones to blame others. Imagine Mourinho being in charge of Spurs, for example, this season with all that has been happening there. It would be a total catastrophe. Poch, in contrast, has for the most part continued on being professional, with the understanding that he can only play his part and blaming others will serve as no help to anyone or to the club. This is not to say that he would never be critical. It is simply the case that it takes a deeper understanding of when to be critical and when not to be in order to make a great leader or manager. That understanding comes from being intelligent. Mourinho lacks this understanding and he has always lacked it.
I have said all of this, and I haven't even gotten on to perhaps one of the most essential aspects of Mourinho - his general outlook on football. Yes, he has won a lot, but like it has been said a thousand times, football has changed. It was always going to change. Just like the narcissistic traits in his personality, his outlook on football mirrors his outlook on life - it's negative, reactive, and regressive. He believes that the best way to win a game is to make less mistakes than the other team. That in itself is such a terrible line of thinking that I don't even know where to begin with it.
So I will conclude with this: we should all try to get past what is necessarily true and what isn't about Manchester United. I don't mean forget it or ignore it, I don't mean not to talk about whether Smalling is good enough or not, by all means we should keep talking about that. But we should primarily attempt to look beyond it for a second. There are a million things wrong with our club at the moment, and it is easy to send ourselves into a frenzy not knowing which thing to start with, or which thing contradicts another and needs no addressing. It is never any help to panic. We have, since SAF retired, panicked like crazy. It has led to many bad decisions and now we find ourselves where we are - with a million bad decisions and an inability to decide what to do next. The truth is - it doesn't matter where we start, we just have to start from somewhere. Sacking Mourinho seems like a good place.