Are you talking about all the effort put into back-porting Python 3 features into Python 2? Or all the random threads attacking Python 3 developers for their unpaid efforts and initiative in making the language better? Or maybe you're referring to the 2020 deadline, which is tortuously long?
It's not that maintainers want to screw anyone over, it's that folks who give away labor for free to maintain libraries want to be able to use the new features in 3.x without spending additional unpaid labor to maintain separate 2.x versions.
And vice-versa, it is not like users have some grunt against developers. They just don't want to go through the pain of having to migrate their applications and the instability that this will bring.
But they wouldn't be able to say "you should use python, we have all of these libraries!" Now, they can. There are a bunch of libraries that run under both 2.7 and 3.5, but they are doing extra work to make sure they work under both codebases and they are refraining from using any of the nice features of 3.5