Comment by tom_b

I think this is particularly insightful. What you've stated is a raw and pragmatic consideration - what is it that I want to do and what library lets me get that done the fastest?

Coming from justin.tv, this insight may be more start-up perspective oriented than historical reasons for programming language choice.

But I also believe that programming language choice is driven by market or behavioral forces that don't necessarily act in a rational way or lend itself to overly rational analysis.