Great point. Intuitively it makes sense that sending kids out when you expect a bunch of their peers to be there is different from sending them out into empty streets. Thinking a little more about why this intuition holds: it's because once upon a time you were sending them out into a community, where they would learn the tried and tested practices by example. Once the link of cultural transmission is severed, it's hard to bootstrap it back again, even if you had a bunch of families that wanted to try.