> Have you ever used a non-technical person's computer for a few minutes? It's like a warzone.
I have used non-technical people's Windows machines, and they were not a warzone. I've looked over the shoulder of plenty of other people using Windows & Mac computers, and generally not seen any obvious signs of malware infestation. There could be unseen malware lurking, but we can't assume that with no evidence.
Maybe this depends on the non-technical people you know, but it's definitely possible for people to use Windows/Mac computers and not be dropped in a pit of malware.