Some people are very ideological about Bitcoin, so they don’t like him because he buys Bitcoin for his publicly traded company using tools they disagree with. These are the Bitcoiners with socialist tendencies and the irrationally paranoid cypherpunk wannabes.
Other people don’t hate him, but constantly criticize him for not doing proof of reserve or not being on board with compulsory funding of Bitcoin developers that focus on things other than maintaining the protocol.
And others are just salty that MSTR, the stock of his company, has significantly outperformed Bitcoin since they implemented their Bitcoin strategy in 2020.