> You says "X is bad", "Y is better" but you don't say how exactly X is bad, in what way Y is better.
I gave you a breakdown in my earlier comment, but I'm thinking that writing more isn't going to make this better:
* Your experience: Python does everything that you need, and quickly, because you are already very proficient in the language and the tools.
* My experience: Shopping for a programming language, knows Python syntax but no attachment beyond that, has tried out a number of languages and has working knowledge of their tooling.
I'm not suggesting that Python is a bad language, just that I think that the tooling and developer experience for new users is not competitive with some other languages. If you are proficient in Python, and haven't tried other languages recently, you won't have experienced the jump: Python is slightly more hard work than Ruby or Node.js, but Rust, Go and .NET Core have a level of slickness and integration that older platforms just don't have.
> What is so bad about "a multi-file Python project that could act as a library as well as a CLI, and be packaged as a wheel for PyPI."
Again, see my previous comment for a list, including some bits that you are omitting. I found that document and read it, but it assumes that you have already created something with docs and tests (laid out in an appropriate directory structure). Since I didn't actually submit the package to PyPI, I didn't have to think about twine, but that's another paper cut. Which is my main point: if someone is not already sold on Python, every small quirk and special case becomes another obstacle, and the Python tooling has collected more than a few.