In a work environment, I don't really mind learning one thing over another (I normally wouldn't touch Java otherwise, for example). I agree that you have to choose the right tool for the job.

My dilemma is more towards choosing a preferred platform. I've been interning for a large enterprise since the beginning of my studies, and would like to try working for or starting a startup eventually. And that's when choosing Microsoft isn't as easy as choosing anything else, even though I would like to.