Come on, you never have berated a golf official?
I'll admit I'm a little confused, your premise is that soccer fans would be better if they didn't know the rules. Yet MWN is claiming that I have an ethical duty to know the rules and I'm vile for suggesting otherwise. Setting aside the fact that we all agree that parents shouldn't yell at refs, which would be better for parents, to know the rules? or not know the rules? or only know rules up to a certain point...which would be?
Yes, soccer is different. In no other sport (non-judging sport) is a single person by design given such wide discretion to officiate, control and set the tone of the game where a single score carries so much weight. I think why possibly American fans get so frustated with soccer refs is they are expecting consistency in calls as they see in other sports. However, they don't understand there is no mechanism for consistency in soccer, as this thread clearly illustrates, and is laid out in the LOTG (refer to MWM's post). This is due to the overriding concept of Spirit of the Game, which is a cool thing about soccer but is a double-edged sword. Heck this thread illustrates that its not even clear what the rules are and that there is a body of laws, or at least interpretations, outside of what is published (granted that the BOL is anomaly, but look at opinions from refs about what constitutes a handball).
I'll say it again, the issue is you shouldn't abuse refs, period. Whether the parent doing the abusing knows the laws, or not, is irrelevant, other than its clear those who don't know the laws are far more offensive to refs.