I was a student from 2006-2011, and it was the same way then (as far as I know). There are no repercussions for not using your tickets, so everyone would just sign up "in case" they ended up deciding to go.

That said, I never had an issue getting tickets for the most part, but it just adds an extra layer of headache that will deter people who would like to go, but don't want to put forth the extra effort (college students can be lazy).

Other schools, NC State I believe is one, utilize different systems where you accrue points for actually attending the games, and demerits for unused tickets. Not sure of the specifics, but they are designed to encourage attendance. More points you have, more likely you are to receive tickets.