> What makes Mars so great for producing software that would cover the added expense of firing a programmer all the way there in a rocket?
I'm not sure if you're asking this question rhetorically or not, but one answer might be that you wouldn't have nearly as many distractions as on earth. No commuting, no Starbucks, no phone calls (from earth, anyway), no going for a walk or a bike ride, no going to the beach - you get the idea. In fact, spending a lot of time working in some kind of virtual, computerized environment might be the only way to keep from going nuts up there.
What's sort of interesting, though, about being on Mars when it comes to an economy is that exporting stuff to Earth might be somewhat questionable. With the exception of digital goods like software and entertainment, the only stuff worth buying on Earth is stuff that can be transported to you, and that would be so costly that your exports better be extremely valuable. While on Mars, if I wrote a program and sold it to you on Earth for $1 million, what good is that $1 million to me?
So other than basic bartering among your fellow settlers, I imagine that you'd probably spend most of your time just trying to survive on Mars itself, without exporting much of anything at all. You also can't trade with the native populations, since there aren't any, which is another major departure from most earthbound settlements.
I think any attempt to settle on Mars would experience many of the same sort of risks that ultimately doomed the Norse settlement of Greenland between AD 985 to approx 1500.