I agree with that generally, but in the case of Python 3, there are real roadblocks at this point, not just intertia. Central pieces are missing. There is not a single postgres adapter that works reliably with Python 2 and 3. It's impossible to write robust web apps using Python 3 because of the WSGI conundrum.

Actually, the situation is very damaging for Python, because Python has momentum _now_ and many new users are confused and put off by the fact that they cannot use the latest Python version for their projects.

Granted, these issues affect mainly web development, which may not be the main concern of a Linux distribution.