Any individual person of company that has internal Python systems is of course fully entitled to decide if it wants to stick with Python 2 or move to Python 3.

On the other hand, companies that are providing SDK's or libraries to interface to their systems have an absolute obligation to provide their code in Python 2 and 3.

Dogmatically sticking to Python 2 is entirely valid for internal systems, but what the heck is the point of providing interfacing code/SDKs/libraries if it does not interface? Google is welcome to keep all its internal systems on Python 2, but all its SDKs should support Python 3. And all Google's public facing developer tools should support Python 3 - nothing else makes sense.

In terms of porting, plenty of people seem to have done it - here's the list: http://python3wos.appspot.com/