I don't get them either, but of course, everyone on my street are of a religion that doesn't recognize Halloween (so I'm sure my apt. really stands out
But before I moved here, the past two places I lived never got trick or treaters. I wish I would, though, because I love Halloween and all the costumes--I even used to dress up and go all out when I was married. My ex and I would always do the house up big and scare kids and everything--they loved it! You could hear them go down the street telling all the other kids to come to our place.
I think its because parents can't trust who their neighbors are anymore.
When I was little, I remember hardly being able to wait until it started turning dark to go out around the neighborhood. And there were sooooo many people out back then. Ahhh--the good ole days.