A lot of parents really don't know the most basic of rules. You can hear it in the stands all the time. I had to move locations at the last game I attended. It was just too much to listen to. As the level of play improves, then so too shall the fans knowledge. But my point of the 3d ref is still valid and needs to be considered.
I asked one ref whom had just been told "I got that terrible call on film", why he does ref. He told me for the love of the game. I respect and appreciate that.
I think coaches could do a lot more by talking to the fans at the games, before the game starts. I know that's a semi-crazy idea but it would help protect the refs and keep them coming back.
The money is FAR too little just justify what they put up with.