Well, that's the problem. It takes a technically sophisticated user to do it. Not an issue for Macs. You can see this in the upgrade rates which are much higher for Macs than for Windows systems. Heck, even at my work with an IT staff trained in Windows every box is on XP except for the very newest purchases which are on 7, probably because they can't get the drivers!
You can't compare XP to windows 7.... 11 year ago OS to 4 year old OS
More than one issue. I was earlier talking about the ability to upgrade and then started talking about the willingness to upgrade. I quickly found with a Google search the graphic I attached that measures the number of systems in any OS based on observed net traffic, taken last April. You can see that Mountain Lion, out 9 months, has more users than Snow Leopard and Lion combined. Lots of people upgraded. On the other hand, Windows 8, out 5 months, had less penetration than any of the previous Windows OSes measured, and ancient Windows XP represents 41% of Windows. Windows users just don't upgrade.
I certainly don't see Mac users running Panther or Tiger (the contemporaries of XP).
Another issue is Macs aren't even in the 6% of total use in business.. Most business's keep XP because some they don't want to upgrade the software and a piece of software can't be on newer machine.
I certainly don't see Mac users running Panther or Tiger (the contemporaries of XP).