Well they don't punish MS
I think they do. Win viruses and spyware are one of the main reasons I switched to a Mac, and why I've never paid for a version of Windows. It could also help explain the rising Apple market share. I also avoid Microsoft Office as there seems to be regular exploits there, and in many cases, Open Office can do the job just as well (or the new software-as-service packages, like Google Docs).
I'm not an Apple fanboy, I think Windows, Linux and OSX all have their strengths and weaknesses.