There is a theoretical limit to the rate at which a society can digest unsocialized people, and this is affected by the exposed surface area of the clumps of unsocialized people. Where by “unsocialized” I mean with respect to that particular society - people in any society are “unsocialized” with respect to any other sufficiently separate society. We seem to have run into a case of serious indigestion. Traditionally we warehoused people who weren’t being digested successfully. Why we stopped is a really interesting question.