I solved it!!! It took me a while to figure it out, but it burst upon me suddenly this morning.
It’s for cars in the winter!!! That’s why you have kids!!! I was sitting in the car running the defrost thinking how much easier this would be if I could run the defrost while someone else scrapped. And then I looked at Albie Dog uselessly licking his butt. And I thought “if Albie Dog was a small child, I could make him go out and stand in the street and scrap the windshield while I run the defrost. THIS IS WHY PEOPLE HAVE BABIES!!!!!”
That’s it, right? So you can have someone to scrap the window while you run the defrost? Otherwise it has never made sense to me, because around the house dogs clean up messes and babies make them, so why would you pick a mess-maker over a mess-cleaner?