Not sure if you guys are trolling or just misinformed. Windows bugs have long since ceased to be the exploit mechanism for viruses; last time I saw a breakdown on it (a year or so ago) it was something like 35% java holes, 25% adobe acrobat holes, 20% adobe flash holes, 10% browser holes, and a small percentage of OS vulnearabilities.
Additionally, since Vista, Windows' "security" has generally been as good or better than its competitors; it had strong ASLR before OSX / Linux, for starters. The issue is that none of that stuff protects against A) buggy plugins, or B) user-executed viruses (aka trojans). The other big issue is that theres been a ton of misinformation on the issue, particularly by Apple's marketing; Im really not clear why anyone would take advertising at face value, or assume that it is technically accurate. Didnt Apple fall FIRST in the first 5-6 Pwn2Own competitions?
And those vulnerabilities exist just to run user-mode worms, in the end - because having an administrator prompt suddenly appear without warning is a sure sign of an infection.
Despite all the rootkits and other stuff, if they can't find a privilege escalation hole, it runs in the background as a user-mode process - you don't need to be root to connect to port 25 or read a user's files, after all.
As for Pwn2Own, the results really are meaningless - if you break OS X, you win a MacBook. If you break Windows, you get a Sony laptop. If you break Linux, you get a Dell. And they aren't necessarily the nicest machines on the lineup, either.
Well geez, Apple, Sony, Dell. If you wanted a new laptop, which do you pick? Most people DO like the looks of a MacBook Pro (even the lowest end configuration is still a nice looking laptop). Then likely Sony comes next (their laptops are fairly good looking). Which leaves the Dell, for those who just want a laptop and try to avoid the massive crowds going for the more desirable units.
Results may be more interesting if they all were Macbooks or something so they'd all be equally desirable.
It's just the same if you offered up an iPhone 5s, a Galaxy S4, a Blackberry Q10 or Z10 and other phones. The iPhone will go first (generally), followed by the Galaxy S4 (it's still a nice phone), and BlackBerry probably will "survive" - does it make their OS more secure? Or just less desirable?