Not all parents are assholes, and as a solo coach, there's no way I could have survived without some of the parent's support with various aspects of managing a team. By the third or fourth season, the parents that had started with me would help wrangle some of the other parents.
This is where we were with one of my kids' teams. Once they got older and split into the elite-national/regional club level (about U12), the parents were not healthy. Over time, the parents started to realize that their kid wasn't likely to play D1 college soccer, so there wasn't a point in being "those parents".
It also helped that a few of us that either coached, played, or ref'd would "help guide" the other parents. It is now to the point where I wouldn't want my kid to change teams because our parents are so awesome.
RIP Bill Oddie.
The funny thing is, I became a ref because I was giving the ref of one of the games I was on the touchline coaching wasn't abusive, but definitely a constant barrage of second guessing. At the end of the match, one of the association members suggest that if I didn't like the level of refereeing that I should become a ref myself. I accepted the Pepsi challenge that rest of history. My favorite experience was a coach that was getting a bit grating. I remembered a line an old timer mentioned that I decided to give a try, "hey coach! you got an assistant? you better get 'em warmed up!"
As a coach, the absolute worst part of the 10 year experience absolutely was the parents. Luckily, I never had abusive parts. It was always over excited cheering for the dumbest things from people that had no clue about tactics and thinking that blindly booting the ball up the pitch was awesome. We had no player with the speed or skill of going over the top route one, so it was just a dumb play. Usually, by the end of the season some of the other parents could usually get them calmed down. It also helped to remind some of the over the top parents that this was recreational play, and everyone got the same t-shirt at the end of the season. Nobody was getting scholarships. It was basically bragging rights for the kids back at school.