I like it.
Musk has always been a fan of the letter X, using it in SpaceX, Telsa Model X, even in his child's name. And since it is his company I don't see any problem with it. Plus it's clean and minimal, and has always been his vision to create a complete app and X represents that philosophy quite well.
I also like the branding and the competition element of the logo design which Elon put out to his followers.
Personally I find the critics towards Twitter/ X amusing, spouting the same shit the newspapers say ๐คฃ