To back what @futurecoach has said, you're going to have complaining with every team.. And predictability also comes with every team. When you're an offensive coach, you're going to add new plays on a weekly basis but you're going to have 8-10 plays that are your bread and butter plays. These are plays that you can run from multiple formations to get different looks, but at the end of the day its the same exact play.
I know from my days of coaching, every single team we prepped for we could identify their 10 best plays, rep those, and be prepared for the game. When we were coaching, if the team came out in certain formations in certain situations, you knew exactly what play they were going to run. It's called tendencies for a reason.
As for the coaches not wanting to coach anymore, Futurecoach is completely right. At some point, the complaining and bickering by parents gets you to a point where you're just done and the enjoyment of coaching isn't worth the additional stresses that are caused. Remember that these high school coaches are essentially getting paid pennies on the dollar to spend an extra 20 hours a week away from their families to help your child.
Obviously not calling anyone in particular out.. just stating things that I observed during my brief career.