Ok, so then you rotate that list through your friends. They might make it tedious to go through all my friends, but if I'm determined enough, I can do it.
People who seriously use this feature will put their secret crushes on the list, and then forget about it.
I come along a few months later, and rotate all my friends through this list, and so I discover which of my friends have secret crushes on me, because I'm not using the feature like you're "supposed" to.
It doesn't work that way based on the international betas, but if you want to believe you've hacked Facebook Dating, go ahead and believe that if it will make you feel better.