During the summer, we camp at the Colorado River in a campground that has full hookups. While we are outside most of the time playing on/in the water, the A/C runs 24/7; that's the only way to keep the rig cool in 110-115 degree heat, and allows us to go inside to fix lunch, take a break from the outside heat, and sleep in relative comfort. I would never even consider camping in that kind of heat without hookups, generator or not. That's not something that I would want to listen to 24/7, much less subject my neighbors to.
However, during the winter, we drycamp at Glamis. No hookups or facilities of any type available, but there ARE BLM rules, including quiet time (10pm till 8am). Now keep in mind, that while at Glamis, you have the constant noise of bikes, buggies, ATVs, etc; many of them quite loud. No problem; it is expected. And generator use during the day for charging batteries, or even A/C use when the weather dictates, is generally not a problem either. But at night, people are generally cognizant of others; generators are turned off, Bikes, buggies, ATV's going out for night rides are started but then leave the camp area. However, we have had a couple of instances that were problems.
Once, while camped in a large circle of rigs, the adjoining camp (also in a big circle) had the rear end of his enclosed buggy trailer near the front of my class C. He ran a LOUD generator all night long right under my window. It literally was buzzing my window. Evidently, he was charging the battery on his buggy, and since the generator was nowhere near HIS sleeping quarters, there was no issue!? At 3am, it finally shut off. Thank you! Nope, it had simply run out of fuel, and 10 minutes later it had been fueled up and restarted.
Another time (also Glamis), a trailer setup across the campground road from us (about 25ft away) ran a loud contractor generator 24/7 for 3 days straight, whether the occupants were there or out riding. The trailer was a rental, and I actually called the rental place when we got home to let them know. They apologized, thanked me for the info, and said that the "renters" were being placed on a "blacklist" and would not be allowed to rent from them again. Perhaps true, perhaps not.
So while most of us don't likely encounter loud generator abuse often, it only takes a time or two to make such a big impression that passions run high when the subject comes up.