The whole article is worth the read. It really bothers me when you hear news reports of little boys being suspended for making play guns in school :( I get the zero tolerance on violence, but think that the administrators need to be using common sense. The examples they give are insane!!
Play is a critical basis for learning. And boys’ heroic play is no exception. Logue and Harvey found that “bad guy” play improved children’s conversation and imaginative writing. Such play, say the authors, also builds moral imagination, social competence and imparts critical lessons about personal limits and self-restraint. Logue and Harvey worry that the growing intolerance for boys’ action-narrative-play choices may be undermining their early language development and weakening their attachment to school. Imagine the harm done to boys like Christopher, Josh and Alex who are not merely discouraged from their choice of play, but are punished, publicly shamed and ostracized.
Schools must enforce codes of discipline and maintain clear rules against incivility and malicious behavior. But that hardly requires abolishing tag, imposing games of tug of peace or banning superhero play. Efforts to re-engineer the young-male imagination are doomed to fail, but they will succeed spectacularly in at least one way. They will send a clear and unmistakable message to millions of schoolboys: You are not welcome in school.
Read more: http://ideas.time.com/2013/08/19/school-has-become-too-hostile-to-boys/ 
I'd be putting up a fight if this happened to one of my boys. I'm glad that our district has gone totally off their walker with recess games. They still allow tag, kickball, etc. and even have a student/teacher tug-of-WAR (oh my!) during field day. Dodge ball isn't allowed just because too many kids get hurt. As far as the claim that some of these games are damaging to self esteem, kids have got to learn that they won't always win or be the best at something. It's called life! There are going to be losses, disappointments and times when you don't always get to go first. If you want your child to not experience these things, than you need a wake up call as a parent.