He's exaggerating (or maybe it's the case at UCSB), since it's usually only true for first year undergraduate (among "traditional" students starting right high school. I think older students usually live off campus). As for relationships, most people end their high school relationship before college, or the two go to a different college, so it's long distance.

I actually found it formative to be forced to share that space and resolve (inevitable) tensions that arise. And since it's usually randomized, you end up with someone you might not have normally met. Of course some people have bad experiences, and can request re-assignment.