There's a God-damned good reason it doesn't and it has a whole lot to do with the fact that Lynn Johnston never really seems to have bothered with this whole "growing up" thing that people tell her to do. As I've said before, the most accurate portrait we appear to have of Lindy Ridgway is timid little Lizzie standing around with her baffled frown trying to figure out the world. One of the earliest Halloween strips had her recoil in pants-soiling horror of a couple of kids in monster costumes. This tells me that Elly's insane belief that having her kids dress up as Almost Zombie or Cinnabun Spice will lead to their being physically assaulted/arrested/gunned down in the street by the police as a warning is a survival of her childhood belief that the costume turns a person into the Galloping Ghoul Of Bullcrapia.
This is probably why part of her hoped Jim would never recover from his stroke. After all, if he started saying things that made sense again, he might point stuff like that out and she'd end up having to be castigated for her foolishness like a child.