You may not want to read this
But, as far as I'm concerned, what is preventing serious growth of Linux is choice.
There is simply way too much of it. The endless distros that do not really offer anything better, but were created simply because someone didn't like something in all the other ones, the endless variations on packages that do not exist because the offer fundamental differences, but because a group of developers fond something principally wrong with the terms of the license (libre office anyone ?), the 36 mediaplayers that ALL have the same issues reading catalogues on network drives.
Anyone that wants to try and give Linux a go is first confronted with a hundred distro's, then 10 or more graphic environments (and don't you dare ask any obvious newbie questions on a linux board or you'll be greeted with disdain and arrogance, telling you to read 10000 pages of information readily available on the internet, you lazy fool), and then the fun really starts, searching for programs you want for specific stuff (try : I'd like an app to manage my CD collection).
If you finally get through all that, why don't you try to get your garmin GPS and maps working. You'll pretty soon find 1000 threads telling you to dual boot windoze or install wHine. Which is exactly what you were trying to get shot of in the first place.
But by this time the general public will have long given up and reverted to Windows. And even if they DO get to the point where they've made a choice on a distro, they pretty soon find themselves locked in again, because if a program is not supported by theid distro or MMI, they have to download sources and start compiling.
SO is there nothing worthwhile there ? Sure there is. But for your average consumer, there are simply too many choices to make, and way too much excrement to wade through to find a few hidden gems.