I think the dynamic you describe above, which exists at the professional and high-level amateur levels, is part of why we have so many coaches yelling at refs at lower levels.
Some coaches truly are screamers, nutcases, but most high level coaches know exactly what they're doing when they get in a ref's ear. I'll use baseball and basketball coaches as the example because they have much more of a role with the referee than hockey coaches do. The first couple of times a coach barks, it's like a warning shot to say "you better start evening up these calls". If that doesn't work, they start getting demonstrative (baseball manager comes out of the dugout, basketball coach gets in the ref's ear on the sideline). All of a sudden, you've got thousands and thousands of people who aren't just booing, they're standing up and screaming at the ref. You've got a whole team full of players giving him the stink eye. As a human being, that's a lot of pressure to apply to your decision making.
So when that next close call comes up, as a human being the ref's natural instinct is to find a way to calm things down and relieve the hostile pressure. That's not corruption, it's just human nature. If he still doesn't cooperate, and makes yet another call in favor of the opponent, it's fairly standard procedure for the coach to go ballistic and deliberately get himself kicked out as a way of activating the full wrath of both the players and crowd. At that point you've got the attention of the media as well, and the ref's at risk of becoming a name the team and crowd will remember in future games. He either eases up, or he becomes the Tim Peel of that league.
Those are all normal dynamics at the elite level, and pro refs and coaches are trained to handle those scenarios.
The problem is that lower-level coaches (and players) see that stuff on television and incorporate it into their idea of how to interact with refs. But at an amateur level none of these dynamics exist. There's no paying crowd of thousands, it's just a couple dozen parents. There's no pool of refs to be shuffled around, it's the same kid week after week. So there's no point in working him like that, you're just terrorizing the guy without any payoff. But just like the beer leaguer who plays an "agitator" role, some coaches genuinely fail to understand that things which are standard in a pro environment are inappropriate in a lower-level amateur environment.
At every level it's normal for people to get upset and argue a call, but at low levels that's where it ends. Both the refs and the players have to be tolerant of each other's amateur status, otherwise it's just not gonna work out for either of them in that environment.