I think they should have accepted the private room if their prayer was disrupting student traffic flow. Would those who support this support Muslim prayer rugs in the commons area too? I don't hold to the notion that any religious group should have the right to disrupt the normal operations of a secular organization, including the schools. This sounds like the kids were trying to be confrontational, or in-your-face about their prayer. My kids prayed with fellow students before high school too, but at their church an hour before school started. Were they truly seeking God's blessings or were they trying to make a political statement?
I'm not convinced it was a traffic flow issue.
It is POSSIBLY an issue of wanting to shove the Christians behind closed doors while other groups can meet at will in the cafeteria/commons area.
If they were blocking traffic--fine--a reasonable issue.
If they were meeting in a corner of a large public room and the administration wanted them unseen behind closed doors while other groups are allowed in the public space, that's NOT FINE.