Games are still mostly Windows, even if the most popular ones are on the Mac; this is due to volume, developer support (e.g. DirectX), and the sheer variety of machine configurations that are open to dedicated gamers.<p>Businesses are also still mostly Windows, and a lot of people need to do work-related things at home. Sadly, you still can't reasonably get work done at a lot of companies unless you have Windows for connecting to some backwards application or server from your company.<p>Finally, many Macs are also Windows PCs. It's not clear if their survey took virtualization into account, or if any respondents were confused about how to answer (is a Mac that runs Windows a Windows PC or not?).