There is something that puts me off about all these languages that want to show off their own strengths by pointing at other languages weaknesses. X in Y is another such pattern, who cares what 'X' is written in, the question is does it perform well, does it serve a need and is it maintainable and secure if it is network facing or otherwise employed in a situation that would require the program to be locked down properly.

Setting up an artificial challenge with rules that favor 'your' language up front is a great way to get the result that you want, but not a great way to learn. Each language has its strengths and its weaknesses, but none of those strengths and weaknesses matter all that much from the point of view of an end user until they have a direct impact on the quality of that which is produced. And programmers have shown time and again they can write crappy code in just about any language (and good code too...) with the language features having a much smaller impact on the outcome than the quality of the people writing the code.