Other recently expired empires, such as the British, Dutch, French, had left some residue for locals grudgingly to admire: habits of administration, a legal system, even just a useful language.
Meanwhile, we parents will continue to explain to our kids, who have already grown up trying to overcome feelings of isolation and difference, that what Lanza did has no more to do with them than if he were diabetic or left handed -- and I'll admire and love my son more every day for teaching me to think out of the box.