* increase exposure of the existing feature, which helps improve
the code health of the entire CPython runtime
* expose the (mostly) isolated execution of subinterpreters
* preparation for per-interpreter GIL
* encourage experimentation
I think I'll ask the followup question - what is the point of those? Why should we increase exposure of an existing feature we know is not fully baked and we know will cause problems with NumPy/SciPy? How will the exposure improve the code health of CPython and who will do the improvement? What is the advantage in exposing isolated execution of subinterpreters? In what way does exposing this feature help prepare for a per-interpreter GIL? What experiments are being encouraged specifically?
And a few of these aren't even heinous! If I happen to be self-taught in the law and I am particularly good at giving wise and helpful legal advice, but I am not actually admitted to the bar, nobody is directly hurt by my advice, but society has decided the potential for harm in this situation is high enough that I still shouldn't be allowed to do that.