I agree with this 100%. Having too many ways of doing things, and no way to pick between them, results in everyone doing things every which way, all different.
That's why this document exists at all. We can definitely make things better, but to do so requires putting together guidelines, proposals, and consensus (things developers are historically pretty poor at), rather than just cranking out code and complaining (both of which developers excel at, especially fueled by coffee)
But we went through that with C++ already: all companies used to publish their own guidelines of what C++ features were allowed and not allowed to use. Of course, all these subsets were different. And of course, if you work on open source project, it's just impossible to be productive in such a language without knowing all of it.
That's why this document exists at all. We can definitely make things better, but to do so requires putting together guidelines, proposals, and consensus (things developers are historically pretty poor at), rather than just cranking out code and complaining (both of which developers excel at, especially fueled by coffee)