AAU ball was tough to watch as a spectator when my son played for a few years.
First, teams in same leagues are grossly mismatched talent wise. Some teams have no reason fielding a team. Losing by 50+ weekly isn't a learning experience.
Second, the top tier teams really should tune it down a notch when up by 25+. Continuing to press at that point is poor sportsmanship.
Third, all the teams featured gunslinging ball hogs. Firing up deep 3's doesn't make you Steph fellas, it makes you a poor teammate.
I know I have a small sample size in this post and my son's teams were usually top quartile, just as guilty of the things above as others. Luckily my kid is a great sport and knew not to trash talk back to the hot dogs or embarrass weaker kids.
AAU doesn't have leagues around us, just tournaments. Most teams that call themselves AAU teams are just travel teams that play AAU events. They also play USBA, YBOA, NTBA or other similar organizations tournaments. There are also a number of leagues that these teams play in and I think that's what you are talking about. Some of the teams involved are glorified rec teams that have outstepped their bounds and it turns out to be bad for everybody.
My son's team has had games where the second half the coach has told them they could only shoot layups with their offhand and only after everyone on the court had a touch. Those games are hard to watch. I'll be honest as a parent I would prefer to be on the receiving end of those games than the team that is winning. At least those kids can get something out of it if their spirit isn't crushed. But particularly at the younger ages there are very few close games one way or the other.
I agree with your point about tuning it down a notch to a point. Pressing while up 30 is ridiculous but it's also the only way some of these teams know how to play. Our coach used to go overboard the other way and I thought it was worse. He would tell the kids "No shots" once we got up 30 and the last ten minutes of the game would end up being keep away. That was way worse IMO. I'd much prefer to just turn off the press but still play basketball.
By the way, we were on the receiving end of one of those beat-downs last weekend. My son's team played in a big national tournament (70 6th grade teams) and played the Toledo Wildcats. They had 5 kids 6' or taller and one kid 5'10". Our starting center (5'8") strained his hip the night before and didn't play but it wouldn't have mattered. They had this kid, Emani Bates, who is being called one of the best 6th graders in the country. He's a 6'4" SF and hit three or four threes including one from 27'. They could have named the score. Never mind that Bates is just over three months too old to be playing 7th grade much less 6th grade. Most of the teams in the tournament were the right age but there were about 10 that we stacked with age exceptions. But we played hard and got the score down to 50-31 with just over a minute to go when Toledo's coach put their starting 5 back in and turned the press on full bore against our bench. They were playing by the rules of this particular tournament with the ages so while I didn't respect what they were doing I was okay with it. But after they turned the press back on I was hoping they would get knocked out and they did in the quarterfinals against one of the other teams that fielded older kids.