I've read a couple of his books, and I enjoy his unique and uncensored views. He's not afraid to say what he thinks, and he's got interesting insights.. These insights seem to piss off a lot of people, but I couldn't really care less about that. It's the content that I find interesting, not how it makes people feel.
As for his linguistic stuff, I don't know about any of that, so I can't comment.
I tell people what my political views are on this and that, I don't see why he shouldn't be able to do the same, just because he's a linguist. People give him a lot of flak for that, but whatever. He's got views, let him express them, even if they're not in his field of expertise. He seems to know enough about things to formulate interesting and plausible ideas about how our world works.