And sure, I understand why people feel a responsibility. And it's fine to take this responsibility too. I'm just saying: there is no need to.
The entire point of this Free Software/Open Source is to give people the freedom to do whatever you want with some piece of software, without having to be beholden to the original author. That's pretty much the entire point.
Anyone in the world can be a maintainer for xz. By forking it and applying useful patches.