Oh sure, I would encourage anyone to learn anything they can musically.
I myself play the drums to a high standard, and then learned keyboard and guitar to a basic. I wouldn`t say it was absolutely necessary, but it certainly helps to be able to play an instrument, or learn some musical theory.
But even then, I learned mainly by listening.

but then to totally contradict myself, I would say a lot of techno producers could do with learning some musicality.

Err, so, I`ve lost the point now?