The bottom line is that most parents are just ignorant. I watched them tear at a friend of mine coaching 13 and under AAU basketball.
He lost a lot of games because the idiots running the league made a dumb rule that you cant foul out. MOst of the idiot coaches took advantage of the rule, and had their players hack everyone on defense, so they could win. He had his team running 3 different defenses, 3 motion offense- and understanding them. He wouldnt let his players hack the other team.
The bottom line is that he did his job, and the other coaches and administrators only with they knew how to do theirs.
The ignorant parents basically pushed him out, and all they did was do wrong, as usual by their kids.