Well, I am primarily a Linux user. All throughout grad school and into my current job, I have not had to touch Windows at all (except for the rare occasion I go to the general lab to do some scanning), so perhaps I'm somewhat qualified to answer this. For a
lot of us Linux users, Linux just makes computers work the way we want it to. Nice powerful command shell, it's incredibly customisable, simple yet powerful programming API, very nifty network utilities (ssh!), the list goes on. The main reason however is
that it comes with kernel source, and I love playing around with it. My area of research interest is operating systems, so having the free source code to the Linux kernel is a priceless feature.
Some of have suggested that some flavors of Linux are better than Windows or Mac because it is free and easier to use and the user is given a choice in a variety of ways (source code, customization, etc). If my parent's can not figure out something as simple
as Mac OS X how can I expect them to understand Linux?
"Better" is quite subjective. For me personally, Linux offers a better computing environment than Windows where I can work comfortably. I can't live without gcc, ssh, LaTeX, vim, apache, grep, python... yeah I know you can install those on other operating systems
too, but I like my OS to have Unix-like behaviour, plus have all my favourite programs available by default.
However, it's not everyone's cup of tea. Graphics professionals may find the tools available rather lacking in features compared to the programs they can run on Windows or Mac OS X. There's also that incredibly steep learning curve before it becomes "comfortable".
I guess I just want my computer to work for me, not the opposite. I am not promoting Windows, Mac, anything, but I believe they have to be a lot easier to use than any current Linux offering. As a student and someone who does not devote his life to computers,
sometimes I just want the easiest and quickest way to accomplish a task.
I use Linux for the very same reason you mention : I want my computer to work for me, not the opposite. I guess I just connect with Linux better than other OSs. But at the end of the day, just use what works for you. I'm not a fan of making someone use an OS
they are not comfortable with, just as I myself do not want to use an OS which I find uncomfortable.