Re: 20 years is a lot of time.
Absolutely right. It's almost like the release of Python 3 was a foreshadowing of the future of the internet and social media; people chose to be outraged, and swore they would stand their ground, because no programming language upgrade should ever lose backward compatibility.
I thought at the time, sure, they will all come round to using the new version when they realize why the improvements were made. But some of them didn't, and still refuse to. I guess they just choose to remain outraged, as is the current fashion on so much of the internet today.
I can't remember the details from back then, but I think there were a few quirky command constructs pre version 3, and there was an effort to make some of the language features more consistent with other parts of the language. I remember reading about people who found the task of transitioning existing code to the new version was not really a great ordeal. I can't be sure tho, I haven't used or followed Python discussion for some time.