By this token, we should be concerned that CPython is not written in Python. But that historically has not posed a significant risk to CPython's longevity, nor to the ability of motivated contributors to learn the C necessary to contribute to it.

(Or another framing: only the tiniest fraction of the Python community was contributing to CQA tooling in the first place. It's not clear that prioritizing the interests of the 99.9% of Python programmers who -- rightfully! -- will never modify these tools makes sense.)