There are many reasons including night of the week, month, team success. These are not meant as excuses, just reasons, reality. A great example is Friday nights in November - high school football rules in ATH, and if several local teams are still in the playoffs, it's going to be nearLY empty.
A couple things that are constant - a fairly large number of games and the difficulty getting others to take tickets when there's a conflict, and a large number of ticket holders come from the ATL.
Again, not excuses, just reasons. Winning of course cures all this. I myself am able to always be there and arrive early, and it IS frustrating to see. I suspect, with the eviction of longtime supporters from their longtime held seats, it will be worse as people not invested in the program move in. (Frankly, now that I know the value of my support, I will not be killing my self to arrive early as I did, and I'm now more likely to blow off a game against Morehouse in November.)
It's notable that all but a handful of basketball teams have these types of issues to some extent - okay two handfuls. keep in mind attendance is reported as tickets sold, so when you watch Georgia on TV then read "Clemson sold out against Miami" it's not necessarily a fair comparison.
