Major upgrades to programming languages often run into difficult uphill battles. From Python 3 is killing Python:
People either continue to write software in Python 2 or they pick another language that did not shoot itself in the face.
I have been building applications and services in Python 3. I’m not blown away by it. It is very similar to writing software in Python 2, except that there is a much smaller pool of 3rd party libraries available.
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There are other solutions, but reviving Python 2 is so obviously the correct thing to do, that other solutions are not worth mentioning.
Clearly not everyone agrees that re-focusing on Python 2 is a good idea.
See also PHP 6 and Perl 6.