Regardless of whether or not Hayden succeeds here, good on him for at least trying. GVR hasn't even made an effort to improve Python's performance (i.e, by most accounts, Python 3 is even slower than Python 2). In fact, he seems intent on actively discouraging such efforts. For example, why is CPython still using a stack-based interpreter, when several people have already worked toward implementing a register-based one and were only met with derision?
I generally agree with GVR's general approach of regarding premature optimization as a mistake, and developer time is usually more important to optimize for than processor time.
On the other hand, sometimes you have to optimize code, and dropping down to C is unnecessarily risky (not to mention tedious, although that comes with the territory). The fact that there's even an alternative today with Numpy and Cython seems to have happened in spite of GVR, not because of him.
I'm sad that someone as influential as GVR would be so consistently rude and dismissive toward an effort at improving Python, no matter how misguided he viewed the effort. This is the kind of attitude that makes leading open source projects suck.
Edit: By the way, I don't mean to imply that I share the pessimism some have about Python's future. Between Python's considerable rate of adoption in upper education, numerics, machine learning, bioinformatics, and various other scientific computing fields, combined with novel approaches to the language like PyPy, Pyston from Dropbox, Nuitka, and Numba, I'm overall pretty optimistic. But it's becoming clear that the committee-driven approach of CPython, driven/impeded by the BDFL, isn't bearing the fruits it has in the past.