Those are not antonyms.

I don't think most people would argue that Musk isn't a visionary. I also don't think most people would argue that Musk isn't divisive.

Definitely a visionary, no argument here

Guess that makes you a visionary too

I know the point you're trying to make, but I can't imagine that even the largest Elon Musk fanboys would disagree that he's divisive. At best, I can imagine them saying it's not his fault and people overreact, but that's still recognition of the divisiveness.

Why is Elon described as divisive? Because it sounds bad.

Ruth Bader Ginsburg was never described as divisive, though she was objectively more divisive than a rich guy who makes cars and rocket ships and flamethrowers. Antonin Scalia was described as divisive, so the argument can't be made that SC justices are somehow different.

It's a rhetorical trick that's been used for many decades. It's obvious, and it's tiresome.