Because I suck... I just didn't manage to jump ship yet. I'd take off time for months to work on my own projects but usually failed to finish what I started. Then money would get low and I would accept the next Java contract to make money again. These days I tell the recruiters that I am leaning towards Rails and JavaScript, but in both I don't really have as much experience as with Java. I did some small things with Rails, but I also don't have the killer combination of design sense and coding skill that the younger Rails devs seem to have. Still, I have rejected most Java projects in the last three years. Might grudgingly look into Android, though (I like Android, but I hate Java, as has probably become clear...).