Hehe, well as I'm sure your boy will soon discover, there are several reasons that that group has issues retaining officials. However abuse is the major factor.
Of the several high school sports I do, soccer is the worst. It's the only time I've had people take photos, follow me, or even try to fight me. From the richest parts of NoVA down to the poorest, parents think it's a great idea to try the guys in the flamboyantly yellow/green/red/blue shirts (I'm betting that doesn't help either
). I blame the professionals. It's hard to find a game where the referee isn't surround by players who are chewing him out over an obvious foul call. Coaches/kids see that and think "Yeah, that's appropriate, I can do that in my game".
Yet I don't see a fix in the future. Soccer has parents get certified and ref if the kids are U13 and under, but most clubs are trying to do away with that. I think that's what we'll see in the future; parents being forced to officiate so their kids will have umps/refs. Maybe, and I doubt it, they'll finally just shut the hell up.
P.S. I think basketball somewhat avoids the problem because we have a handle on the coaches/kids. You do a quarter of the dissent in soccer in a basketball game and you'll be ejected inside 6 minutes. And I assure you, my group has been heavily recruiting these past few seasons.