I think you should respect his choice, but we can argue about the reasons and argumentations for that choice. I don't know if Mr. Stallman has siblings. But if not, it means that his bloodline will end with his death. Let that sit for a moment and think about it. Think about the hundreds of people in your ancestry that lived through world wars and the dark ages and all kinds of other "bad times," compared to the hund…
You can certainly pass values down to the next generation without having kids.
But let me give you an example. My ancestry is very well documented back to 1100ish.
Most of my ancestors had either a military function or later on were law enforcement officers. When I grew up, my parents left me the choice to do anything I want.My grades were good enough to go to a University and become a doctor or lawyer. But since I've been a child I had a natural desire to protect people. I did that in school. And well I am retired now, but I did that for all of my life more or less.
This could of course just be imagination as there is no scientific proof.
But I think that some of these values were passed down our bloodline. And that is just different than learning values from someone else. It's like an imprint.
So if you decide not to have kids and you don't have a brother or sister who can keep the bloodline going that is an absolutely fine choice, but it's also a shame that that genetics and traits that were passed down for centuries get lost.
English is not my mother tongue, I hope you can get my point.