Suffering from hypothermia?
Many are enterprise users, and this can mean a strike against Google Apps. Many of them stick with XP because it works great for their purpose and many applications only work with IE.
Like it or not, Microsoft wins a lot of points for supporting older versions for a decade plus. They might lose a few bucks on a new Windows license but make it back on reputation and other enterprise tools.
A company still using an operating system released 10 years ago probably sees little merit in migrating to hosted email, calendars, etc. They most likely have an old Exchange system that they are maintaining alongside those XP workstations. I doubt this affects many organizations.
Windows XP might have been available for a decade, but you have to consider that Vista flopped and Windows 7 only arrived around 3 years ago.
That means large numbers of organisations were still installing Windows XP as their standard desktop around 3 years ago, and possibly even more recently than that since they wouldn't necessarily have evaluated Windows 7 and set up to migrate to it from day 1.
Moreover, the days of upgrading hardware every 2-3 years are gone, at least in typical office environments that aren't really pushing the performance limits of a typical office PC any more.
In other words, for large organisations that keep relatively up-to-date, it's still entirely possible that they have a lot of WinXP machines still around today, even if their newer machines are on Windows 7 now.
It doesn't matter that they are enterprise users. Enterprises have held back the state of the art for decades. The fact that google has to drag them into the recent past and hear this much screaming is only an indication of how backwards they are.
The world is changeing and the enterprises will have to adapt.
