Actually, Linux is used more than we realize. A lot of non-profit organizations probably use it as their operating system, since they can't afford to pay a lot of money for MS. They also need something easy to use, since many of the users are from third world countries, where most aren't experts on IT.
I first heard of Ubuntu from Nabuur. A non profit organization that uses the internet to connect volunteers with those who needed help. One of the tasks was to test Ubuntu. There is a great need for affordable open source material. Something that is easy to use as well. Ubuntu is just that.
I also believe that UNESCO supports Linux, as open source material, like it supports all open source material that is easily accessable . Since adding a new Linux distribution is as easy as downloading a link from the internet or from a live cd, which can easily be burnt, how much better can it get. And how much do you want to bet that those free laptops donated to students in Africa and other places, had a Linux distribution, for no other reason that it was free.
Unfortunately, since these users don't speak up, they go unheard. But they do count... more than those who fork over the money for a commercial OS.
So Linux started as a hobby... so what. So did Google, and many other wonderful things. In fact, many great ideas started from somebody's garage. Thank God for young people like that. If it weren't for them, we'd be in the dark ages. And thank God for such nice things as Synaptic as well. Who ever thought of having everything in one place was a genius.