Actually if you ever wrote code that you wanted to make backwards compatible with Python 2.7 is a nightmare. The fact that they did not even wait until 2020 before depreciating it is a testament to that.
> I've considered that as more of "Python 3 is a bad thing" by splitting the ecosystem further, and creating additional churn and rework of existing projects. Thus my question of why people seem to think this is a good thing now -- i.e. what has changed in Python 3.6 that they're happy to do this now when they were pissed off about it a couple years ago?
I don't know about others, I always been supporting Python 3 since 3.4. I feel like many people were complaining about Python 3, but never used it, then eventually started using and realized that it is not so bad.
> I may do that.
You should, is much more enjoyable experience. Perhaps because you're so used to Python 2, you don't notice, but Python 2 has a lot of warts that accumulated over the years.