Subjectivity clause
From Superdickery
Although one may discuss why they like a particular item (music, movie, etc.), or even the merits of it, one must ultimately agree that taste is purely subjective, therefore it is considered poor form to remark that someone's tastes are bad.
This rule does not apply to the webcomic Achewood because it's an unfunny piece of shit. Did I mention it sucks? I don't think I did. Achewood sucks.