You can do plenty of things with Linux without devoting your life to it. Lots of non-technical people use it just fine (although their needs are often better met by tablets). Even for more technical uses, most people who actually have a use for it don't have that much of a problem. Most people find a Windows computer or a Mac meets their needs better.
Macs aren't locked down. They're the only computers you can legally run all three of Windows, Mac OSX, and Linux on. iPhones and iPads are locked down, although still useful, but this is an area where Windows just isn't competing well.
Having done several Windows and Linux installs, my experience is that one is about as easy as the other. When I do parallel installs, sometimes one gives me problems and the other doesn't. As far as "free" goes, if the system didn't come with Windows (like my last two desktops), legally installing Windows is fairly expensive.