The left hates Elon Musk for the same reasons they hate Donald Trump:
He's a class traitor who defected from the party line orthodoxy of the ruling elite.
He was a darling of popular culture — the real life Tony Stark — who switched sides because he cared more about the truth and about reviving America.
He's built hugely innovative companies from scratch instead of coasting on a garbage credential or a worthless college degree.
He put himself beyond the left's control — and they hate you when they can't control you anymore.