Public schools are not allowed to promote any religious worship but they cannot stop anyone from engaging in religious worship on their own either. In my view it's better to have a room set aside to encourage the students to stay on school grounds. If a group of Christian students asked for a room for prayers it would be granted. Of course that may never happen; I woukd guess that youth from the old Christian stock in general fully embraces secularism and has abandoned religion. Atheism is one of the fastest growing minorities in North America thanks in large part to these millenials.