Elon Musk is either trolling (most of the time) or tweeting while upset (e.g. name-calling a British diver -- who initially randomly insulted Musk, telling him to shove his submarine when he was just trying to help), either way you can see some sense behind his actions, even if they're puerile or mistaken.

On the other hand, Jack Ma seemed to very confidently say and dismiss a lot of things without evidence.