I really have 3 reasons for deciding to do this.
First, I liked unix from the first time I used it. It’s very flexible.
Second, I expect that in the next few years the growth of linux is going to continue. There is likely to be a glut of Microsoft Certified developers in the market. So, my guess is that the demand will be for linux programmers.
Third, because linux has been developed primarily by people who were doing the development for the shear enjoyment of it, I expect that the work will be more sound and elegant. People programming for income and on dealines are much more likely to cut corners and be less thorough in their work.