None of my friends (including the ones that are now married) that I know of ever attended a singles event. The reason is/was because single events have a stigma for being “loserish” (This does not mean that everyone who goes to a singles event is a loser). A guy would rather not go to one of these events than to swallow his pride and attend one. (This includes plenty of guys who do not have lists and lists of girls. Contrary to popular thought in theyeshivaworld forum, not every guy has lists of girls to go out with).
Furthermore, I find it hard to believe that there are only 60 single boys left in the world. So the lack of boys attending these events is not because there are no single boys.