I find it interesting that the criticisms of his statement all leave out the rationalizations that
immediately follow it. I view that as important context.
Were does he say he hates the people doing it? Nowhere. He merely says "I hate double spacing".
You seem to be making assumptions about his reasoning. I think it was fairly clear when he said "Because what else would you hate over? I don't want to even think about the possibilities of facing stupid landmines like that."
If you are gonna judge people by what typographic conventions they hate and "don't wanna know them", then I don't wanna know you.
He's judging the top comment based on their statement of how they judge. I think that's fair.
Keep in mind, someone stating they don't want to know (associate, have as a friend or acquaintance, etc) you isn't necessarily an insult in the common sense. When backed up by reasoning based on evidence, it's not asserting anything not already known about that you. Any insult is based on respect you must have for that person (whether specific or general to the any person). When on the receiving end of this statement, it's up to you to determine whether you care what that person thinks, and if so, whether your behavior need examination.