I have a hard time calling a kid a "bad person." They might have poor work ethic or a bad attitude or might not get along with teammates, but they're kids. They're still learning how to be a person. I think it's at least worth it to try to correct the issue, even if it may not work most of the time.
But bad parents? Yeah, they gotta go. That's never gonna change.
And yes, I realize the kid with all those problems I listened probably is the result of bad parents.
Meh...define "kid". If kids can commit violent crimes, a kid can most certainly can be "bad". I deal with teenagers, and a few of them over the years could be accurately described as "bad people". No, they weren't murderers, just self-absorbed jerks. Their peers know what they are, and will tell you all about it given half a chance. Funny thing though is that their parents can often be nice people. I know it's counter-intuitive, but that's actually a pretty good indicator that it's really the kid. The parents realize their kid's personality sucks, they just aren't able to fix it. How many times have we seen kids grow up with good parents, but they turn out to be crappy people? It usually surfaces before they're fully grown.