To make it a bit tropey, a sheltered kid is much more susceptible to people luring them out of their safe space with promises of excitement and Things Their Parents Would Not Approve Of.
Of course, the data (e.g. teen pregnancies) shows that this isn't a universal / statistically provable truth, but still. It makes sense in my head.
I mean, not really. 'Unsheltered' kids that face hard reality are the ones that end up in gangs.