Personally (FWIW), I think you're doing the right thing. Arguably, you should be able to boot anyone you want for any reason you want. Your house; your rules. If you don't like the vowel/consonant ratio in their posts, they're gone. If you decide you suddenly have an aversion to the letter "J" and want to boot everyone with that cursed letter in their name, they're gone.
But besides being the owner, you're the administrator, and it would be unseemly, at best, to boot people for other than the reasons you've already stated via the rules.
Besides, he's a pathetically easy target. One of those "love to hate" characters. If he'd just shut his gaping maw for a while, some of us would actually be a little disappointed.
Anyway, people should (IMO) be booted when they're causing harm (threats, spam, etc) that is best addressed by their removal.
In a case like this, where someone is being resoundingly refuted and we all really see them for what they are, I don't believe any administrative action is called for.
