But they're not. 56% of students attend a local school. And other than a few specific campuses, it's not like colleges are isolated from the rest of the community. They go to the same grocery stores, parks, restaurants as everyone else. And if they did go away to college, they're just near someone else's loved ones.
I'm not even really sure what the point you're trying to make is.
Again, it's not like boozing, vaping, and fornicating are exculsive to college students. In fact, I'm not sure they do it any more than any other age group or more than their non-college peers.