It is mostly Christianity and its values (and perceived intolerance) they oppose, not the state endorsement of religion. I suppose if you could ever force them to be honest with themselves, they would grudgingly concede the point, while justifying it on the basis that Christianity, with its pervasiveness in this country, is the only religion whose dominant influence (and very nature) jeopardizes our tradition of religious liberty. (Of course, that is absurd on its face, since America is the freest nation in history largely because of its Christian roots.)
In their zeal to honor the wall of separation between state and Christianity with the ostensible goal of promoting religious liberty the secularists have trampled on that very liberty. That is, by twisting the Establishment Clause beyond recognition, they have, in many cases, emasculated the Free Exercise Clause.
This has happened most prominently in public schools, where in their mania to prohibit the state (the public school) from endorsing religion, they have suppressed the free exercise rights of the students. For example, schools sometimes forbid references to Christ by commencement speakers, because they apparently believe that to permit students to voluntarily exercise their religious freedom or expression is tantamount to the state endorsing the Christian religion.
But the state is no more endorsing the Christian religion by permitting the valedictorian's reference to Christ than the government is endorsing my convincing arguments in this essay by not infringing on my freedom to express (and publish) these profundities.
In the case of UWEC's ban on RA-led Bible studies, if we give the school the benefit of a huge, unwarranted doubt, we could conclude that it wasn't specifically targeting Christianity, since it nominally applied the ban to other religions.
But either way, it is still grossly infringing on the free exercise rights of its RAs and its students, all in the interest of avoiding any appearance of "unapproachability" on the part of the RAs.
You see, the presumption often adopted by our cultural elite is that Christianity is, on its face, intolerant. Doesn't everyone know that any RA who would lead a Bible study is less approachable, especially to members of other religions?
In the name of protecting all hypersensitive students' non-existent constitutional right to be free from the slightest discomfort at the hands of the state (most of which anticipated discomfort is likely a figment of the imagination of those paranoid about Christianity), this university has chosen to violate the most important right our Constitution does guaranty: religious liberty.
The only "separating" usually being done by the fabled "wall" is the severance of religious liberties, mostly Christian, from the Constitution.