Because the simple fact of the matter is it isn't a terrible OS in the eyes of the average consumer. It mostly performs as advertised and is a "free" upgrade. Think about the reasons there was backlash against some of Microsoft's other recent OS busts - Windows ME-Unstable as hell, Windows Vista - slow as a dog, annoying UAC prompts, and lack of driver support. These are all things that most people can see and experience. Unfortunately, being spyed on by media companies is turning into an average daily experience.