Not just for a peachy bum.
Benefits to strengthening your glutes are numerous and are the reason why all of our training at the studio involves some form of gluteus activation and butt work. These benefits include:
1 Tighter core
2 Stronger back
3 Faster running
4 Tighter pelvic floor (this is a big one [for girls AND boys])
5 Stronger legs
6 Fewer hip and knee issues
7 More junk in your trunk etc etc
Life changing buttocks.
While typically viewed from an aesthetic perspective the benefits of having a strong derriere are very functional and I would go as far as saying life changing.