Why should it? A reference implementation is just that: a reference, something that implements all of the specs perfectly, to give other implementers something to model upon and test against. A reference implementation is not meant to be the fastest or prettiest, just the most compliant.
I will never understand why this still hasn't been picked up by the Python Foundation and worked to be the reference implementation of Python.
Official stance is that Python Foundation care about Python as language, and Python C implementation is best vehicle right now to progress Python.
Transition (when/if it comes) will be made from ground up. That is, Python devs wont think hard about abandoning Python C unless some other fully compliant implementation get dominant usage share...
(And such switch would negatively affect Python progress in short term, as devs would need to reeducate themselfs for this new code base)
There was some Google I/O with creator of Python (about GAE), with Q/A sections, where such topics where brought if you like to know more.