I get it. Watching some of the videos of him giving tours around the SpaceX facilities, he comes across as a real first-principles thinker. So much of tech disruption is applying first-principles thinking to problems and coming up with better solutions. Given that he's so great at it, I can see why people look up to him for it, his companies are clearly successful for having built things from first-principles – electric cars, rockets, etc.
Except... of course... it's not that simple. "First-principles" thinking is a nice buzzword and it's rooted in some truth, but it's an excuse for university engineering graduates to ignore real world problems and consequences, and jump to solutions that are certainly disruptive, but often disruptively bad, and rarely overall an improvement from the status quo. It's pure naivety, and as someone with a lot of self confidence from unearned privilege, it's something I'm constantly battling against inside myself. Can I really do a better job than experts? Probably not.
Is SpaceX much better than competitors? Yes, but not entirely because of first-principles thinking, there was a lot of winning the right contracts and clever business decisions from Gwynne Shotwell. Is Telsa much better for its reinventing the car from first-principles? Not really, it was for a bit, but the vertical integration has so far borne out fairly low quality cars relative to their price. What about Twitter? Well Musk dropped in to a working business to re-evaluate everything with that first-principles thinking and look where it's got him. He was naive. He didn't value the expertise of those actually doing the job for years, and he's effectively destroyed the business.
So yeah, I get why people like him, and in moderation I think those aspects are worthy of respect. However Musk doesn't do moderation, and so it just comes across as naive.