CPython is still a naïve interpreter. PyPy beats it in most cases, sometimes by a lot. Of course, PyPy still has a GIL for the same reasons CPython does.

So your complaint is that GVR doesn't want patches that would (significantly) regress performance for the majority of use cases, yes?

IIRC, IronPython single-threaded performance was competitive with CPython.

Multiple ones already do.