I agree with Paul, and I mostly agree with Myk.
And that is because deciding whether or not it is suited to the average home user is NOT about whether or not it is hard. Rather it is about whether or not it is familiar to a majority of people.
I have a Computer Science Bachelor's and Master's degree. I've been using Unix since 1987, and Linux since 1998 in my career.
But when I started a new job that involved supporting Windows, it was HARD because I didn't know enough about it. It was unfamiliar. (It also has an incredibly stupid design and horrible security, but that is another matter.) Ask your average user to edit the registry and see if they can do it. Ask your average user to start mucking about with DLL files and see if they can do it. Ask your average user to find where their email is stored on disk and they probably don't know. (Heck I still bump into people who confuse the Monitor with the Computer.) BUT, and this is the big one, every town has umpteen stores with geeks in them who might be able to help you, and everyone has friends who use Windows, and so on.
Linux just doesn't have that market penetration. I fully believe that modern Linux (Ubuntu is my favourite for "it just works" in the Linux world) is just as hard as Windows. But it still is less familiar.
...art
ps: and don't ask me for advice, Larry, I bought my wife a Mac precisely because it is familiar to her and far simpler than Windows, and I have since bought myself an iMac also at home also. And I still think Windows is annoying and stupid.