I also spend a lot of time at Opti and other monohull regattas. You would be disgusted and appalled at what happens there... rarely a protest and never any circles). That, and the callous way some OAs feel about changing class rules for individual regattas makes me cringe, twitch and drool.
Some of the best protest hearings I've sat(as a judge) were at High-School Regattas. The competitors were polite, straightforward, and appreciative. Even when the ruling went against them, they've thanked the PC, shaken hands, and accepted penalty without complaint. The sailors din't dispute the decision but often asked what they did wrong and how to avoid making the mistake again. It's great as long as we can keep the coaches away (we came close to throwing a coach off the premesis once).
The most combative and least mature competitors often come from PHRF (big boat) racing. I worked a very large regatta once that spawned two Rule 69 hearings.
In adult dinghy racing, there seems to be an aversion to protesting. I think people view a protest as an accusation of cheating (which it is not). It's simply enforcement. Also, there's a desire to avoid filing a protest on shore because it delays the party (particularly for cat sailors), especially if the regatta outcome is not affected.
Personally, I don't believe that the "good old days when people followed the rules" ever truly existed. Human nature has not changed - nostalga has simply clouded our memories. For the most part though, I think sailors at the club level generally show great personal integrity when it comes to following the rules.
If, however, competitors witness rule infractions and don't protest, then they don't deserve to complain. They are (how shall I put this politely)... not part of the solution.
Regarding class rule changes, see RRS 87. Sailing instructions may change a class rule only when the class rules permit the change, or with written permission of the class association.
Sincerely,
Eric