Well, the teens learn some discipline and following orders. The criminals learn not to do whatever it is that got them community service. Everyone wins.
You make it sound so black and white when in reality everything is gray.
I happen to know a few "criminals" and they're not bad people they just choose to do shady stuff. Although I've met a few that i instinctively distanced myself from because you can tell they're always out to trick you or get something from you it's usually not that simple.
Some of them were even punished way out of proportion to the severity of their crime.
I don't know if most kids have the skill to deal with these people and since the crafty ones come off as overly friendly they might even get lured in.
It's probably not idea to mix clueles teens with street smart criminals.
I think the fear is the mixture. So you take impressionable youth and force them under legal obligation to spend more time with elders of their socioeconomic group who selected a life of crime often than time spent with their own parents. What could possibly go wrong? Optimistically they'll be scared straight, but ...
It's not like they're sending people sentenced to 40 years hard labor for robbing a bank to community service at the recycling center. They're probably mixing with people who got first-offense drunk driving or disturbing the peace charges.
