Few things are impossible to code. It's hard to create a JIT for Python and the reference implementation for Python is not the right place to add such a JIT for the reasons stated in the comments above.

It's not that the Python developers preventing discussion, it's just this discussion is always fruitless, has been had many times before and the people invoking the discussion often blame the cPython developers for their response. Nobody wins, it's a waste of time.