It is a joke. Accidently banging an underage is something that happens, and all things considered it's no big deal. It's funny. It's funny like watching somebody take a nutshot, where you're like "oh damn ur fucked now lol". When one of my friends does it I laugh and make jokes about them being child molesters and getting raped in prison, and ring them up at 3am to scream "I AM HER FATHER AND CONSEQUENCES WILL NEVER BE THE SAME". When a celebrity does it I laugh harder. But all in all it's not a big deal. It doesn't make them a rapist or a predator and it doesn't colour my feelings towards them, it's just a thing that happens and is funny. Maybe in the future it'll become socially acceptable to ask somebody for photo ID before you bang them, and this sort of thing will happen less, but that's not something that works out well for you in the real world.
The only people acting like these guys are vicious gang-rapists who literally dragged an 8-year-old off the street and then had Chris Kluwe bleach the evidence and pay off the relatives are gamergate spastics. Everyone else is like "oh snap they got jailbaited lol w/e no big deal", because it isn't a big deal. Sometimes 17 year olds want to bang you and don't tell you they're 17. It happens, and I imagine it happens more if you're a professional athlete. Who cares?