This article would have you believe that if you tried to use Python 3 that within hours you would hit a library roadblock that would be a showstopper. Completely wrong, and you have to ask why the author wants to create this perception.
Python 3 works beautifully and is a pleasure to program.
If you WANT to hate Python 3 then you'll find no lack of ways to hate on it for the next 20 years (HEY! I found some package built by a fellow Python2 holdout! See, it simply is not possible to write the code to upgrade it! PYTHON 3 IS FINISHED! THE SKY IS FALLING!) etc etc ...
If you want to succeed with Python 3 then that's easily done, you just get on with it.
No one using Python 3? Flat out lie. Prove me wrong by scientifically explaining your assertion that no one uses Python 3. Lies, spoken to back the wishes of the Python2 holdouts to sabotage Python 3 - they hate Python 3 and will say any lie to bring it down and spread the FUD. I'm wrong? Prove it in detail with science. Alternatively make vague, handwavey statements about downloads, as though that defines how many people are writing code today with a language.