This: "[X] is faster at runtime and python is faster at development time."

I wish more people knew / recognized / accepted this understanding of Python's goals. There is the old but still quite accurate: http://www.python.org/doc/essays/comparisons/

I'm not sure if Guido is the original author, but he at least comments on it. There are also quite a few excerpts going back to the origins of Python where Guido plainly states that the goals of the language are ease, brevity and developer productivity - I've never seen performance as a stated goal.