Reply #79: the schools would be saying that religious clubs are not eligible

[Charlie Brown]

to hold meetings that other organizations and groups hold after hours (like Pride Clubs or School Democrats). An observer could construe that other groups were being given an edge that religious groups were not getting. They could argue that people of faith were being treated differently than other groups of students, and that the school was trying to deter religion.

I've heard that argued before, and they do seem to have a point. That's probably why the current law is that if any club meets, religious clubs are also eligible to meet.