> On both OSX and many Linux distros, Py 2 comes pre-installed but Py 3 does not.

Because python 3 was not the most stable at the time of distribution of that operating system. Why would I the developer of said operating system release anything but the most stable versions of the language? This would in turn make my operating system at times less stable.

I totally agree. However, until Py3 is packaged standard it's always going to be easier to run Py2 code. For example, I have a friend who does data analysis on OSX and occasionally she gets data in a format that is ugly. I take a look at it and send her a python script that will massage it into something nice.

She's ok with the occasional "sudo pip install ..." to get a library, but if my instructions started with "ok, first install Xcode and then install homebrew" the answer would probably be "it's ok I'll just do it by hand"

Simple script like that are unlikely to be much different between Python 2 and 3 unless you are using specific libraries. Just make make all the "prints" into "prints()" and "Exeption, e" into "Exception as e", and I can't see what the differences would be.

The difference is in the effort required to make it run at all!

It already is in many distros.

sudo apt-get install python3. Or Whatever the OSX equivalent is.

Its not that difficult.

Arch comes with Python 3 as default.

OSX doesn't come with a package manager.