Two Paragraphs of General Remarks about Linux
From what I've encountered "distro-hopping" this past year or so, the most critical barrier to wider adoption for Linux isn't lack of high-end software, marketing, or all that but, rather, hardware compatibility. "It's come a long way, the kernel," is certainly true, but it's also true that for every 30 steps forward, one or two things break. Upgrading to Ubuntu 12.04, for instance, required that I create a .config file for my Intel wireless card which, as far as I can tell, was supported just fine in the 2.6xx kernel line.
Of course, I also think that people who are solely focused on "defeating Microsoft" and "bringing Linux to the masses" are a little misguided. Aggressive proselytizing is annoying and often a little unbalanced in motivation. If Linux is to grow, it will grow, and hopefully at a good pace where healthy innovation continues and the community doesn't being to suck, for lack of a better way of putting it. Think of all the bloating and forking now. Imagine that with 100 times the userbase. Those people who place great import on high-end software are usually professionals, or connected to some. They focus on the software because they, and their circles, need that software to feel comfortable in Linux environments. Pulling in more contributing members to the community will do more to create healthy long-term growth cycles than installing Linux everywhere -- though, certainly, that could work too somewhere down the line.