Quite true, a rewrite can help if it is also a "rethink". But you don't have to switch languages to get that effect--in fact you'll probably do better if you do

Quite true, a rewrite can help if it is also a "rethink". But you don't have to switch languages to get that effect--in fact you'll probably do better if you don't throw a new language/library into the mix. My point was that, contrary to what is apparently a common impulse, rewriting the same thing in a different language while maintaining the lack of attention to performance considerations that was present in the first version isn't going to help much.