The issue isn't whether he's making an ass of himself, he certainly does that anytime he gets a platform to speak on regarding general topics. I think everybody knows he does that at this point. So what.
Why should I care if Musk makes a fool of himself when trying to talk about anything outside his competency? Why would I become emotionally charged about such a meaningless topic? His detractors do, they can't control themselves. It's because they now view him as someone to fight with in the forever culture war; they previously viewed him overwhelmingly as an ally, prior to the Trump years.
At issue is whether people can be rational enough to control their emotions and separate out Musk's obnoxious personality, the way he broadcasts it often, from the factual reality of his accomplishments.
The need of his detractors to strip him of all accomplishment, is plainly pathetic. It's easy to recognize both good and bad in regards to the life of a person, without lying and pretending someone like Musk is just all bad/negatives (terrible person, zero accomplishments - that's the detractor position).
They view him as a political and cultural opponent (to one degree or another). If you're their opponent, you must be entirely destroyed (not partially, entirely). Since we live in a culture of extremes in terms of politics / partisanship. Their opponents can have no good qualities, no positives, they're all nazis across the board.
George W Bush garners a lot more sympathy/ respect from the same exact people than Musk does. The guy that launched a war with Iraq that got hundreds of thousands of people killed in the following civil war, he's more likable than Musk per their views. That's the insanity we're dealing with. Because Michelle Obama likes Bush, and Ellen Degeneres likes Bush, the Clintons built a rapport with the Bush family, so golly gee he can't be all bad, tee hee, it's so cute how he paints and stuff. The same people called Bush a nazi while he was in office. It's because he's no longer viewed as part of the culture war, they called off the attack.