Blaming the followers for not reading the docs is an easy excuse, when the real problem is that the leaders have failed to define Python. The PSF needs to decide what precisely Python is and what it isn't among themselves. Because they did not do so, they can't tell if something is a bug or intentional. See this entire thread as proof.
In lieu of a formal definition, the maintainers resort to a hodgepodge of user docs, PEPs, mailing lists, and the "reference implementation". Worries about making that "reference implementation" more complex stymied Python's development. There's been flamewars about this topic with the PSF and their apologists.
On that note, Rust encountered a similar problem of bad decision-making by maintainers, who also were opposed to specification. They have ejected those maintainers and replaced them with ones who understand the need for a formal definition of their language.
I'm not arguing against the notion that Python doesn't need a more rigorous language spec. But I don't think that's the blocker for alternative implementations with significantly high performance - the parts that are well-documented already provide a lot of leeway to optimize if only user code didn't rely on it.
And if users don't read the docs today, I don't see why they'd suddenly read a formal spec tomorrow if one is available. The problem is that Python got successful specifically in form of CPython, making the latter a de facto standard whether it wants it or not. I understand the users, too: why should they bother writing implementation-agnostic code if they're planning to run it on CPython anyway, and the vast majority of developers who might want to reuse it will likely do the same?
In lieu of a formal definition, the maintainers resort to a hodgepodge of user docs, PEPs, mailing lists, and the "reference implementation". Worries about making that "reference implementation" more complex stymied Python's development. There's been flamewars about this topic with the PSF and their apologists.
On that note, Rust encountered a similar problem of bad decision-making by maintainers, who also were opposed to specification. They have ejected those maintainers and replaced them with ones who understand the need for a formal definition of their language.
https://blog.m-ou.se/rust-standard/