How about "if you don't like Musk, don't use X or buy a Tesla?"
I personally don't really like any billionaires at all, but I'm not going to get in to a hissy fit because someone uses Microsoft Windows or bought something from Amazon.
The first thought that comes to my mind is that the people in Twitter are just going to migrate to another social network. It won't be problem solved, it'll be problem moved.
The second thought I have is the amount of hate and comments full of misinformation on sites like Facebook. Should we ban Facebook too? And if so, where does it stop and who is it that gets to decide that a site is getting banned for "wrong think".
Personally, I believe this isn't so much a petition against X, but a petition against Musk, who I think wouldn't be absolutely gutted even if X went out of business. I think he bought it with the aim of derailing anyway.