I have direct answer from a hoshuve Rav that I quoted before about attending a class on comparative religions. The answer depends on a person. The permissive side is based not just on tuning it out, which will be a waste of money for this particular class, but on a positive need to be able to “know what to answer” when operating in academic environment. But this is an extreme and not the most practical example. Not many Jews get into different religions in college, but liberal/socialist ideas are dangerous. I’ve seen sad reform parents who are in serious business, had a son returning from campus not just with a nonjewish girlfriend but also a trotskyist. So the virus is out there, question is whether kids are protected enough. As I now can hear high school and college classes live at home, I can hear a bunch of teachers diverting history, English, biology, even physics into liberal discourses. Not all, not even a majority, but sufficient enough to be dangerous. I would suggest to everyone, try this for a year, and then you will actually see where your kid is holding when under attack, and then decide whether they can go on their own. My in-family estimate so far is about 70 percent are ready…
Maybe gadol as a risk analyst can give us some numbers on risks out there… You saying that many pass the test is not enough, we need to know how many didn’t pass and what is your definition of passing. Many here would not want kids to end up with some of the views you find acceptable.