Its that microbenchmarks are useless. If it was worth my time, I could come back and use any of the available python tools (cython, numba, etc.) to compile that

Its that microbenchmarks are useless. If it was worth my time, I could come back and use any of the available python tools (cython, numba, etc.) to compile that function to native code from python syntax and achieve native speed. Or I could write a D implementation of {{some relatively complex matrix algorithm}} and compare it to numpy, showing it was slower. You could then respond by saying that I wasn't using D optimally, and I'd agree.