I think that's a good point about the size of the crowd affecting perception about the rudeness of the fans toward the officials, and perhaps in a broader sense...
At a college football game, when 60,000 fans boo the officals en masse after what they see as a blown call, it's just seen as part of the game, we say "boy, it looks like the crowd didn't like THAT call," and we move on.
At a soccer match with an attendance of 100, when the half-dozen fans/parents who think they understand the rules yell, "Hey, Ref, you need to learn how to use that whistle" and the individual words are audible on the field, we talk about how rude, inconsiderate, and obnoxious soccer fans are.
