You know, this environment is probably as close to the Hobbesian state of nature as it gets in modern first world countries. The solution to that has traditionally been for society to create a government to hold over itself, a leviathan able to be applied to. Thus, violence is curbed, by the threat of intervention by the overseeing power.

As in the world, so in this microsim.

Is this a desirable state? As someone who leans more towards the libertarian side of things, I think the answer is no. But despite that, there are two very valid points. The first is that like it or not, this is how the world is. You can try to set up an alternate system of governance, but if you play in a certain society, you play by their rules. Or overthrow them and institute your own rules, but that is a task of much greater scope.

Second, there has to be some rules. Life in the state of nature is nasty, brutish, and short, after all. In the "state of middle school", it's not short, but it's pretty nasty and brutish. This problem has to be overcome somehow, and the established way to do it is by government, that is to say in this case by authority figures. Have you got a better way? Many libertarians over the years have tried to hammer out alternatives, but as of now it's still an open problem.