This rule assumes that the most popular behavior is not being a jerk. What if you're the only black in a city full of racists whites? Are you a jerk because other people treat you badly? A less extreme example - what if you're the only person who doesn't easily understand the complex social structures that exist in workplaces? People will treat you badly because you were too nice to the low-ranking guy and not sucking-up enough to the high-ranking guy. That doesn't mean you're a jerk either.