That if I may say so, is a very blinkered view. The main reason for windows issues is that a lot of people use it, and so its worth the hackers time to get past the protection, whoever it is by. If miraculously Linux was the main OS then I'm certain you would have a similar situation there as well. My feeling at the moment is that much of the malware seems to get in not just because there are ways in Windows, but mostly due to the ignorance and gullibility of users who will do daft things like open attaches without even knowing what the file extension is and who go toweb sites of a dubious nature because some email that might possibly be from somebody they know had a link to it.
Very few of the infections seem to come from drive bys or direct attacks these days, aminly, I'd imagine as they have a trail direct to the nasty person or a machine botted by them.
Msse seems to catch most of the normal run of the mill stuff, as do most of the virus scanners, but there is always going to be a trade of between being able to use the machine easily and the are you sure, are you completely sure type of stuff that false positives generate quite often in avg, avast and Norton for example. Just remember, there is always going to be the first person to encounter a new nasty designed to get past your anti virus system. Brian