We have seen countless of dramas here especially when you go to the Reputation Board, and these kind of insults has been one of the topics, it's not appropriate for a ban, as the only thing you can do here is to ignore the guy.
Sad but true. At least it's easy to ignore that sort of ignorance. I've seen a lot worse get left unmoderated though. Considering there's no personal information, doesn't seem to be any lies (just ignorance), and it's happening on forum, the best thing to do is probably ignore the user. When people start posting personal information, spreading lies, and harassing users both on and off the forum, that's where it becomes an issue with me, and even in that case (Vod) the user never had any action taken against them by the Administration so I am certain nothing will be done here.