- without breaking anyone's code (did that for the print function etc and delayed py3 adoption for a decade but not for the most user requested feature which is speed)
- No large PRs (how a 5x speedup can take place with small patches that no one figured out yet?)
- a small team (not enough money, less risky if they tried to adopt other pypy-esque projects that are more advanced speed wise, a more comprehensive plan that would invite donations, I would certainly give. For this presentation I don't know)
To back up that fact: Python 3.10 will remove long-deprecated features, see issue tracker: https://bugs.python.org/issue41165 and What's new, the Removed section: https://docs.python.org/3.10/whatsnew/3.10.html#removed
The Python 3 debacle is a beautifully worked example of why being backwards compatible is so important, and I can 100% sympathize with them not wanting to go through that again.
Among interpreted languages python is/was one of the faster ones.
NodeJS has similar speed, and in some cases is faster. I don't know any other interpreted language though.
People are also complaining about GIL, but ironically NodeJS is single threaded.
The only production language with performance in the ballpark of Python is Ruby.
I agree that more often than not it simply isn't an issue, but CPython performance isn't much far ahead of toy languages, for a whole lot of reasons that we are all sick and tired of hearing.