Define "prone". Define which version of Windows are you talking about. Wnidows 98? From a technical perspective Windows 7 is better protected safer than OS/X. It's true that there are much more malware for Windows but this is a tradeoff that people should make: more available software (including malware) vs obscure platform with very limited software choices (and here Ubuntu ar better yet VMS will spank everything

)
Yet,
W7 is vulnerable to 8 out of 10 viruses out there.
W7 remains vulnerable, and prone, regardless of the "technically better protected" spin MS has been promoting.
Perhaps. So what? There is much better selection of such software on PC side anyways. One can easily pick up available free software which will be better tha what comes standard with OS/X.
Larger selection? Perhaps.
Better selection - quite the contrary.
Furthermore, the majority of free software, available on Windows, doesn't even come close, in terms of interoperability with other apps, features, and capability.
It's just FUD. What about iWorks or Safari?

In reality, as always with PCs, you have options. You can buy PC with crapware (and save a buck or two) or without. No choice for Mac buyers.
The alternative leaves much to be desired - so much for choice.
To uneducated people, everything is confusing. Again, it's about choice. Windows is used in so many areas that one version of OS simply would not be able to cover all bases. It speaks t the strength of the platform and, once again, about the choice selection PC buyers enjoy.
Why not offer 'Ultimate' for everyone, then, at a reasonable price point?
The fragmentation here (cripple ware) is a major put-off, especially for users who evolve, only to discover, later, that their version needs to be upgraded.
Other than being a significant hinderance to productivity, it is royal nuisance.
Another uninformed opinion (or deliberate FUD). Microsoft had experts (real ones, not the genius types) helping people within the framework of Microsoft MVP progra (
http://mvp.support.microsoft.com/) since 1993. Unlike genius bar, this program is available to people living anywhere in the world. It's free and you get help from real professionals.
Go MBPs! This site is more dedicated to the adulation and glorification of their Most Valuable Professionals, than anything else - sweet.
Another FUD. Consumers were happily buying PCs with Vista ever since it was released. It was the big businesses that did not switch but they have their reasons (like millions of application they need to port before switching to new OS). Obviously Apple does not have this problem because not a single serious company in the world uses OS/X as a main OS.
The embarrassingly low percentage of Vista sales is made that much more dismal, once one factors in, that many chose to revert back to XP. (myself included)
FYI, a fairly significant number of Media, Recording, Graphics, Publishing, and Advertising companies use OSX as their main OS. Many more have recently switched - all in all, this would seem a far cry from "not a single serious company..."
speaking of FUD.