I agree that this type (and all types) of rude behavior should be discouraged.
it is infrequent and only a few
Thankfully, during the past 2 years in which I have been a PerlMonk, it is my experience that they are few and far between. Because of that, these instances do tend to stick out more.
Periodic reminders, such as this thread, may be one of the most effective means to curtail unnecessary behavior. Another mechanism is to send a private message to the offender with a reminder of netiquette. In my opinion, taking the high road, as your linked Monk did, is always the best approach.