I have to say even as a relative newcomer to Python, I find a fair bit of truth in this:
Working in a non-homogenous (that is, heterogeneous OS) environment where Python 2.x vs. Python 3.x is not guaranteed, the lack of backwards (or forwards) compatibility is problematic. If nothing else it erodes trust in the language – will Python 4.x inflict similar pain? Should I be looking to yet another language that isn’t so willing to shoot itself in the foot?
Not all environments, even if they should be, are Puppet-perfect and portability is still a major requirement.
This is to some extent what happens when languages become religion and “purity” to ideological dogma becomes more important than functionality. While I have to praise the desire for perfection, sometimes the perfect really is the enemy of the good.
All that said, as Python becomes more “native” to my mentality, maybe I’ll change my mind. I’ve found the transition to other languages, OSes, etc. offensive to my sensibilities only to later become “assimilated to the Borg” as it were.