I don't think he claims to be a corporation here.

What he says is that, because wordpress[dot]org is his personal site, telling him what to do with it would violate his First Amendment rights.

Its still stupid. The first amendment doesn't mean you can do literally anything you want.

I've come to realize that for some people the law is considered in a Big Lebowski manner: "that's just, like, your opinion, man".

A billionaire who will remain nameless is reportedly very fond of saying “Sue them” when he’s not getting his way. It’s the lawyers job to figure out what to actually sue them _for_.