This is a cop-out; I’ve been to plenty of elementary schools as an adult where there were teachers on the playground. A teacher’s job is to educate students, and that’s a job that demands they interact with them outside of their classroom and subject. This doesn’t have to be an everyday activity, but a teacher who spends every recess huddled in his/her classroom is, quite frankly, missing an opportunity. The ones who think it’s all about putting their lesson together are the ones that drone on for the sake of hearing their own voice, then blame the students when they don’t understand their obviously-superior command of the subject. I’m frankly not surprised such teachers don’t go out on the playground; they’re not very good teachers to start with.
And frankly, even if there weren’t teachers on the playground, any competent adult ought to be able to supervise a playground. If “tag” was getting out of control on that Colorado playground, the solution is to get better supervisors. If they don’t have enough supervisors to do the job, hire more. In short, deal with the issue, bag the excuses like “not enough money/time”, and do the job.
Really this argument can be made about many physical activities. Would you likewise ban wrestling as a PE activity, which allows kids to throw other kids to the ground? Or bouncing on a trampoline, which allows kids to fall from potentially dangerous heights? The key in any of these is to teach kids how to do these things safely with proper supervision and guidance, yet still allowing them to learn something from the activity. I’m not necessarily a fan of dodgeball, but it’s clearly a method for improving hand-eye coordination and general agility. Minimizing the risk of injury is important, but declaring it evil because it “encourages kids to throw things at each other” is just silly.