I maintain multiple Py 2-3 compatible codebases, both academically and commercially. It's not hard, because I develop in Python 2, while writing Python 3 compatible code.
Python 2 is a beautiful language as powerful as:
print "Hello, world!"
If Python is a different language and should be treated like so, then I don't want to switch to this other language, or have a project support two different languages (I'd switch to Go if having to switch languages). For all intents and purposes: Python 2 works just fine. Google did not need Python 3 when they first released TensorFlow a year back.
> If you start a project today and make it Python 2 + 3
Then you are compatible will the largest amount of users. That's what matters to me: Somebody on a fresh install being able to pip install my library, no matter if it is Python 2.7+ or 3.4+. All other reasons are politics.
> this isn't about corporate employees or banking apps from the 90's.
No, it's about banking apps from the 00's and 10's.