The fact you think that way is part of the problem in America and a large part of society as a whole, especially the south. They did something bad, so they must be evil, so we should throw them in a cage (because that is going to help in 15 to 20 years when they get out of prison) without trying to figure out why or how we went wrong as a society raising them.  
If half of the things these boys did are true (and seeing they were found guilty, its safe to say they are) then you have to ask where it came from. Where they abused as children? How about the kid who had no father growing up, how big of an impact was that? Studies show no father makes you exceedingly more likely to commit crimes as you get older, and studies show victims of sexual abuse are more likely to commit sexual crimes. 
Telling them we hope they rot in prison or how they failed doesn't make the world a better place. Hell, putting them in prison doesn't make the world a better place because their deeds are already done and will never be undone. It's a punishment to them, not a protection to the outside world, because the fact they weren't able to be identified as people who could commit these crimes beforehand is the protection we pretend putting them in prison affords. What these boys need is years of therapy on top of this prison sentence to try and figure out the real meaning behind it, and then we use that information to try and target people in the real world with the same symptoms and signs to make sure it never happens again.