Regardless of how "caught up" we sometimes get into these games, as adults, we all must remember above everything else these are children's games - played by children. IMO, there are a few strict rules that should be followed by adults when participating in children's games, whether it be as a coach or a spectator.
1.) IMO, after a game is in progress, coaches comments should be restricted to his/her own players/staff and umpires - no one else.
2.) An opposing coach should NEVER direct comments at an opposing player unless it is in the form of genuine praise - such as "good catch", etc. If a coach feels the need to comment about an opposing player, it should be done in privacy with the umpires and opposing coach.
3.) A very wise veteran of the sport once told me: Spectators "spectate" - Coaches "coach" - Players "play" - PERIOD.
Children's games generally get very ugly and NO FUN for the kids when these rules are violated. As adults, we need to sometimes do a reality check to keep things in perspective.
So, how do I know this? From experience. I once had a nasty habit of yelling at referees in my DD's 4th grade basketball games!! Talk about a reality check... looking back, that was about as idiotic as it gets. BUT - that reality check took hold, and I developed a habit of biting my tongue and pinching myself to remind me that THESE ARE KIDS playing a KID'S GAME!! I have found the best recipe for a cure is focusing on catching an opposing player making a great play and giving her genuine praise. By practicing that, it is far easier to ignore negative people who try to drag you and the game down to their level. And it teaches the kids to do the same.