Lots of researchers made millions with new computer technologies, but you preferred to keep developing Linux. Don't you feel you missed the chance of a lifetime by not creating a proprietary Linux?
No, really. First off, I'm actually perfectly well off. I live in a good-sized house, with a nice yard, with deer occasionally showing up and eating the roses (my wife likes the roses more, I like the deer more, so we don't really mind). I've got three kids, and I know I can pay for their education. What more do I need?
The thing is, being a good programmer actually pays pretty well; being acknowledged as being world-class pays even better. I simply didn't need to start a commercial company. And it's just about the least interesting thing I can even imagine. I absolutely hate paperwork. I couldn't take care of employees if I tried. A company that I started would never have succeeded -- it's simply not what I'm interested in! So instead, I have a very good life, doing something that I think is really interesting, and something that I think actually matters for people, not just me. And that makes me feel good.
So I think I would have missed the opportunity of my lifetime if I had not made Linux widely available. If I had tried to make it commercial, it would never have worked as well, it would never have been as relevant, and I'd probably be stressed out. So I'm really happy with my choices in life. I do what I care about, and feel like I'm making a difference.
Didn't you fear you would lose intellectual property when you released Linux?
I didn't think in those terms (and still don't). It was never about intellectual property, it was about all the effort I had put in, and it was about the project being something personal. But yes, I was a bit worried that as a totally unknown developer in Finland, somebody would decide to just ignore my license, and just use my code and not give back his changes. So it worried me a bit. On the other hand, what did I really have to lose?
Also, quite frankly, looking back, it wasn't something that really is worth worrying about. First off, even if you're the smartest man on Earth, and you write something really interesting, it will take you years to do. In other words, it will take you time before it's really even worth stealing. So if you start making it public early on, don't worry about people and companies trying to steal your work. They'll probably not even know about your work, and they'll certainly not think that it's worth stealing. And by the time it is worth misusing, the project is already well enough known that people can't really misuse it on a big scale without getting caught. So the very openness of the process actually protects the developer to a large degree.
So have people used Linux without following the license? Sure. Copyright isn't necessarily honored in all parts of the world, and there are nasty people and companies that just do legally dubious things. These kinds of things happen. But once the project gets big enough for those kinds of things to happen, there really isn't any point in worrying about them. The people who misuse the project limit not you, but themselves. If somebody uses Linux without following the GPLv2, they just limit their own market (they cannot sell it legally in the developed world without having to worry about the legal side), and they won't get the advantage of open source that the companies who follow the license get.