Forget the on-court and on-field aspect... the reason why SU fits in the ACC is that we have a large, passionate fan base. Among many things I dislike about the Big East, the biggest perhaps is that half the teams in it have no friggin' fans! I mean look at our greatest historical hoops rival, Georgetown... they have no fans. Most of the fun in a rivalry is the antagonism between fanbases. Well that angle is kind of missing when your rival has no one rooting for them! Most of the hoops onlies are in the same boat: Seton Hall, Providence, St. John's, DePaul... all black holes.
This is why I always tell you guys why the ACC is significantly more valuable than the Big East, even though they may not have been as good lately in hoops, and a toss-up for football. Because even when UVA, Maryland, NC State, FSU, etc are down they still have thousands upon thousands of fans that care, and watch. It's about being big time, and SU is big time. That's why we fit.