A few quotes from an interview with Pete Skomoroch at the Metamarkets blog:
Some of the best data scientists I see often have worked in a few different domains. I think that helps with creativity and problem solving. A nice way to sum data scientists up that I’ve heard: “They’re better statisticians than your average programmer and they’re better programmers than your average statistician.”
Working in different domains is good for people who are intellectually curious and just like solving problems in general. It can be a challenge, but it keeps life interesting. You see commonalities. If you take a really good data scientist and they’ve been working in bioinformatics, and then you drop them into a consumer internet company, they can often ramp up fairly quickly, pick up some domain knowledge and then start solving problems.