I don't want to disagree with your core point, because you're right; to a certain extent, OS X has always needed more defenses against malware than it has owned up to.
But you can't find a large-scale Windows deployment anywhere that hasn't had to deal with an actual in-the-wild malware outbreak. Security people in corporate America do malware cleanups for Windows several times a week.
At the same time, you'll have a hard time finding anyone in the real world that got hit by "Mac Defender".
but that is because the target plane for OS X is so small and not worthwhile. If OS X was 95% of the corporate market and made up large networks it would be targeted just as regularly as Windows is. there is nothing technically superior in OS X that prevents it from being a malware target (prob inferior to win7)
But you can't find a large-scale Windows deployment anywhere that hasn't had to deal with an actual in-the-wild malware outbreak. Security people in corporate America do malware cleanups for Windows several times a week.
At the same time, you'll have a hard time finding anyone in the real world that got hit by "Mac Defender".