Somehow, through the years, disgruntled parents came to believe that if they didn't like the school system, complaining was an answer. When the complaints were long and loud enough, the school would support the parents instead of the faculty. Teachers and administrators make up the structure of the educational process. They are professionals with the knowledge and experience to do their jobs. Let them.
Coaches are also professionals. They know your kids; sometimes better than you do. Kids let their guard down with them. When coaches are around your kids 12 hours a day, they get to know kids very well. When was the last time you spent 10 to 12 hours a day, 180 days a year with your son or daughter? Please, please, don't reply that teachers/coaches are paid well. We know better, don't we? Figure it out with a calculator. When teachers/coaches are with your kids 10 to 12 hours a day, ask yourself, "Who's with their kids?"
For those whom you condemn as worthless and want to replace, think long and hard. Did you criticize your children's teachers in front of the kids? Did you make jokes about them? Do you yell and scream obscenities at coaches as well as other players at games? Words that injure and degrade the project that you, as parents, came to observe? Participation is for the children. They earn the right to play or not to play.
If you have made these mistakes, correct them. Adopt a rule of thumb: Support the school, the coaches and the teachers in front of your kids, kindergarten through 12th grade. If you or your spouse think something unfair, don't be unfair yourselves. Please don't knock the people in front of your kids or their teammates. What values are you teaching by whining and pointing the blame at the coaches?
The kids lost the game. Kids who could have studied or practiced harder. Instead of making these mistakes, call the teacher/coach quietly. Speak to them at parent-teacher conferences. That's what the teachers want. Secret meetings that are not secret from your children are very damaging. You teach disrespect as well as the philosophy of "my parents will fix you." Is it the teachers' fault always? Could there be a remote chance that your children have heart but are not state material in sports? Do you want respect? Then teach it at home.