My understanding of it is that the primary division between Windows and Linux is the ability to legally see and alter the source code. The sort of person who wants (or would like) to see what exactly is happening under the bonnet prefers Linux. Windows is the choice of closed-source because of its ubiquity. Apple is the choice of closed source software for those prepared to pay the premium for stylishness.
As long as home and development use is affordable, I don't think that cost is really an issue. Production licences are things that companies pay for and are the consideration of managers and those in charge of the purse-strings.
As we have seen with OSs on mobile devices, it is not a love or respect for Microsoft that makes Windows popular. Indeed, it is not inconceivable that another OS is the default desktop OS in 10 years' time. InDesign replaced Quark as the DTP-standard within a couple of years in the late 1990s. Lotus 1-2-3 was the spreadsheet king until the late 1980s.
If Microsoft were to make the source code for Windows freely available on a GPL-like licence, then many of those that love Linux would come to love Windows *as well*, once they had found a way to customise it to their wishes. The majority of people want an OS that just works. No hassle, no spyware, as few updates as possible. They want much the same as before but a little nicer  They don't care about the OS, it is a necessary evil so that they can play their game, type up an e-mail, use Skype or make a DVD with family photos and videos.
 Consider the furore over the Ribbon in Office 2007, the new layout Windows 8.1, the success that was Windows Vista.