Even if you're under the impression that he's going to resist "education" on how it's expected for users to behave on this site, I feel like you should still leave a comment explaining what bothers you about his contributions. I've been in many situations on the internet where someone who I thought was going to be hostile when approached in a civil manner turned out to be understanding and kind.
He's certainly passionate about gaming, or he wouldn't have written that rant about greed inherent in game design these days, and I feel like this, along with a slight misunderstanding as to what sort of tone is expected in an answer(don't post rants, post answers), is responsible for the tone of his answers. So if he's willing to understand that his tone isn't doing him any favors and improve the quality of his answers, I feel like he could be a good user.
As for what to do with the answers, here are my views:
- If his answer isn't answering the question, as is the case here(or was), flag it as not an answer.
- If he's trying to answer the question but his information is wrong, downvote and leave a comment explaining his mistakes.
- If his tone is what's bothering you, either downvote or edit, and then leave a comment asking him to be more polite.