If I may, you highlight the problem by ignoring my point. My point is that the lack of a stable, consistent, easily targetable platform for third parties is what keeps that software out of user's hands. Sure, if we had a billion desktop Linux users, I'm sure no amount of headache would come between revenue sources, but we don't. Therefore, don't you think that actually making it very easy for third parties to write and distribute their own (not necessarily open) software would yield a higher chance of getting them to throw a few resources at it? That's a rhetorical question btw :)
Take this example. A long long while back, I installed the Amazon MP3 downloader. Now, I don't even know if it works any more because I've long since switched to using a Mac to download music. But at the time, they had to independently package the same application for a number of different moving target "platforms". Only a small number of vendors (like Amazon) are going to bother with that effort, and perhaps because their own engineers want this to work :) And 6-12 months later, when the distros have revved, those packages no longer work because system libraries and other pieces have changed underneath. Sure, I can and did fix this for a while for myself on my own system by using compat libraries or building stuff from source...but users aren't going to do this, and vendors writing these apps aren't going to go rev them every 6 months just to stand still. No, they (rightly) expect that if you install a software application today, it's going to work in 6 months, or 3 years from now. Maybe not in 10 years, but in 10 minutes from now it had better still work.
We can go back to thinking the answer is that we ignore proprietary software, or non-distro stuff. That's fine. But that is why it will never be the year of the Linux desktop. It won't be the year of the Linux desktop until a user can download a piece of software built more than 10 minutes ago, and not by the distro in question, and expect it to just work. And sure, we can all go out and buy Macs, etc. etc. but that's not the answer either. Let me summarize it this way: the Economist article has a number of very valid and useful points that should not be ignored.