Also unless there's some data about people's frustrations, I find it hard to believe ~4% of computer users previously with Mac and Windows got frustrated enough to switch to Linux. Are people but a tiny minority on sites like this frustrated with either OS?
Anecdotally, I don't know anyone in my life who has switched to Linux this year or last year. I know people on Linux but they were already on it. Again completely anecdotal, but I go out to coffee shops, Barnes Noble, libraries, student centers, and co-working spots frequently in various cities in the east and west coast. I rarely if ever, see Linux being used.
I'm not totally convinced by the report either but mainly because I can't get at the data, sampling methods etc. To be honest I didn't try too hard. That said, I would never rely on anecdote - there is a damn good reason why we both automatically mention the word whenever we spout off in a forum such as HN.
I'm a KDE aficionado for good reason. I put a few large icons (KDE allows you to scale your icons really well) on the desktop, with a pretty wallpaper, that have easily understandable functions, that are locked in place. The ability to lock the desktop layout is a killer feature that I do not see available on Windows or Mac or most Linux WMs.
Obviously, it does help that I'm an IT Consultant but "For an average user, Linux can still be quite challenging to use as their main OS." No it doesn't need to be so. The KDE Plasma UI can be made very simple or unbelievably complex to suit the required UX.