I took a pass at Python 3 a while back. The amount of hoops I needed to jump through, to deal with compilation errors around Unicode handling, was terrifying. It was simply a poor user experience.
Python 2.7 just works. Sure, it's a nightmare past a certain scale point. But until you get into the dregs of OO it really is executable pseudocode.
Python 3 is some other language that lost that property.
The big problem is that we don't ship languages with telemetry that reports when they fail to work. So things that are completely obvious to outsiders never make it to inner circles. Not that I can really see any way for Python 3 to mend its errors.