I don't care who wears a Sigma Chi pin Lamda Chi pins on the other hand...
. But no, I don't think non members of any group should be wearing a badge of an org. I don't think most of these ebay buyers do anything with these pins besides buy them, sell them, and show them off, possibly donate them or whatever, but I doubt they go around wearing them. Of course, I realize that there HAS to be someone in the wide world of sports that does wear the badges they buy, whether they're a member or not.