The fact that you think CV parties are for idiots says less about them and more about you and your lack of knowledge of herd immunity And lack of appreciation for freedom.
The two problems are, first, these people make be asymptomatic or only have mild symptoms, and then will spread them to compromised friends and family; and, two, the jury is still out on whether antibodies confer immunity.
It’s risky behavior: that much is clear. If such actions were isolated specifically to a single group of students, that might be one thing, but if there’s anyone believing that all of these students would immediately self-isolate for the next 2 weeks after contact, then they should think again. They could easily endanger others... so yes: while I believe in herd immunity (I remember chicken-pox parties), I don’t believe that having idiot college kids try to self-administer that is a good idea.