Reasons:

He is a petty person; he called one of the divers saving Thai children a pedo, tried to get a lawyer fired for successfully suing him, is suing the firm which forced him to buy Twitter

He fights unionization while tesla has safety and racism issues, and just look at spaceX on glassdoor

His securities fraud, plus dogecoin pump and dump

He dislikes mass-transit and blocks actually helpful transit ideas with Boring & Hyperloop

And ofc his management of Twitter leaves much to be desired