Ultimately, Linux is doomed on the desktop because of a critical lack of content. And that lack of content owes its existence to two key factors: the fragmentation of the Linux platform, and the fierce ideology of the open-source community at large.
My two cents
Yes, if ever an operating system was driven by innovation—but constrained by ideology—it’s Linux (or, to phrase it in a way that pleases certain ideologues, GNU/LInux). I remember trying to hop onto the desktop Linux bandwagon a few years ago, only to get constrained by self-righteous mailing list administrators who demanded that everyone send e-mails in plain text (no freedom here, only the abysmal line-break formatting caused by all different email clients, not to mention those ridiculous ` `fake quotes” glyphs and mediocre Unicode support). This isn’t 1980, it’s 2010.
Strohmeyer, R (2010). Desktop Linux: The Dream is Dead. http://www.pcworld.com/businesscenter/article/207999/desktop_linux_the_dream_is_dead.html, accessed 20 November 2010.