A good friend of mine recently switched to Linux wholesale after sitting on the fence for a while.
He's a smart guy, but not a technical whiz by any stretch -- usage pattern is about 50% HTML/CSS editing, 30% graphic design and 20% gaming. He knew all of the keyboard shortcuts in Photoshop, was pretty handy with Dreamweaver, and knew enough MS Office to get done what needed to get done. Unfortunately he was also re-formatting his machine every 6 months due to the usual Windows bit-rot, and he'd pretty much had enough of that. I'd been using Linux for about 7 years myself, so I suggested that he get himself a copy of Ubuntu. He had installed it on his own a few days later (one of many non-technical people that I've seen get through the install unassisted).
It's been about 18 months now. There were the typical "where is everything" questions at the start, and it took some time for him to cozy up to the idea of using a command prompt once in a while, but it would be impossible to say that he's not better off now. Inkscape replaced Photoshop, vim (!) replaced Dreamweaver, and Google Apps replaced MS Office. But more than simply replacing what he already had, using Linux somehow enabled him to quickly develop a whole new skillset. After doing nothing but HTML/CSS for 12-15 years, he's writing PHP now, and he's pretty damn good considering where he was a year and a half ago with no coding experience. He's every bit as good with vi as he was with Photoshop. And he's even installed Ubuntu on his wife's laptop, and she's rapidly developing higher technical abilities as well.
One thing that has struck me watching new users is how quickly people seem to "get it". If they have preconcieved notions about Linux, they're gone after using Ubuntu for a day. After that happens, a sense of awe and wonder seems to set in and they gradually become genuinely curious about computing. My friend's wife was a hunt-and-peck typer who knew "how to do email". I've since heard her telling others how to use apt-get and she knows how to remotely access GNU Cash on their home server (X11 forwarding over SSH) to do accounting. She even knows what that means, and it's only been several weeks.
To the parent poster, I'd say if you tried to do your job in Linux at all, you didn't try very hard. Or you started with a distro that is ridiculously overwhelming for a beginner. If you want a real reason to use Linux, delete every program from your Windows machine that you don't hold a valid license for and see how much "work" you can get done. Or imagine what else you could have spent the money for your Windows/MS Office license on next time you're forced to re-format because your system just isn't as snappy as it used to be.
Windows became so ubiquitous because it was (is) so easy to pirate, and now we have a whole generation of computer users that think anything other than Windows is "wrong". I have yet to see a single Ubuntu user who gave it an honest try go crawling back to Windows.