I'm not sure if you even understand what makes a good manager. Why does Tom Muller work for SpaceX? Did you ever ask that question? Tom Muller was identified by Elon and recruited by Elon.
Great managers understand how to identify and attract talent, they understand who to promote and who to fire, who to listen to etc. If Tesla and SpaceX are doing well (and I'd argue they are both massive successes), then a huge part of that is down to Elon's hiring and people management skills, along with his strategic vision.
If Elon was such a terrible manager, he wouldn't have as talented people working for him. Also, if he was such a bad manager, he wouldn't have hired or found those people in the first place. One of my good friends (an engineer) recently left my previous company to go and work for Tesla, part of the reason he did that was due to Elon Musk. You can choose to dislike him, but people go to his companies often because of Elon himself.
One axiom of successful leadership or management is that the value of any leader is the total cumulative value produced by all the people under them in the leadership hierarchy since they are influencing, directly and indirectly, all of those people. We can rate Elon's success as a manager and leader as extremely high, because SpaceX and Tesla are hugely successful companies.
it's really not because there are plenty of reasons why those companies are successful, none of which can be traced to Elon. If people want to fawn over someone they should pay some respect to Tom Mueller who actually builts the engines that make those rockets fly.
Again, if he is such a good manager, which of his moves were that great? In concrete terms, rather than just giving me some argument from correlation.
I would really like to be convinced why i should believe that those companies are successful because of, not despite of him running them. History has more than enough examples of horrible managers in charge of great businesses.