This is a good post.
I, too, have coached both my kids in youth soccer, basketball, and football.
And, I think this rule is ridiculous.
I will tell you that there is always that one d-bag coach that brings out “rules” like this.
For example, in one of the leagues I coach in, the league is a co-ed league for 7-9 year olds. There’s one coach that only takes 9 year old boys on his team. He wins nearly every game by (no exaggeration) 15 goals, all the while yelling out instructions like “Kill it” (at least he’s referring to the ball, not the opposing players...I think), “Keep on the pressure, they’ll crack again”, “their goalie can’t stop any shot, keep drilling it right at the goalie”, and other instructions that seem just a little much. The one time I saw a team giving them a real game (meaning the score was “only” 5-3, in their favor at the half), he went bananas on his team at the half. I was half a field away and could hear him barking. The team came out and scored over 10 goals in the second half. I guess he can be proud of his motivational skills. Course, the guy has been coaching the same team since my son was in the league 5 years ago.
Again, this rule is stupid. But it’s usually idiots like this who make people think this rule sounds reasonable.
Came across one team where the coach had obviously coached his kids as if it was the competitive league, maybe even European style soccer. Very physical, lots of contact well above and beyond simply getting getting open or trying to get past a defense. It was plain their gameplan as coached was intimidation over skill. We didn't sink to their level, instead we rested our fastest players and late in the game put them in - they ran around the brutes and we beat them by 2. ;-) However, my co-coach did "invite" their coach to have some discussions about sportsmanship out behind the public restrooms. He's about 6-5 and 250+, oddly enough, the opposing coach declined the offer.