Wubi is one of many ways legitimately advertised to normal users as a way to install Linux. I read up afterwards on its horrible virtual-disk issues, but if people can't be made aware of these issues, they're still going to try it out of convenience.
Oh, and I believe you when you say that GUIs worked to set things up. What I'm not sure about is whether that involved everything; (setting up the programs I want to use, like Eclipse, getting wireless drivers working, installing Adobe Flash Player, changing the browser so that it doesn't use some non-standard search engine by default). I can safely say I have NEVER successfully installed Flash Player without using some incomprehensible command line copied out of some tutorial webpage.
Sometimes I think part of the benefit of software working out of large corporations is that they push for centralization. There's really only one version of Windows 7, barring the tiny differences in release editions.