Here is something I think doesn't get discussed enough in the rabid parents vs. childfree arguments (which I think are annoying in the first place).
Having a child rewires your brain to prioritize protecting your offspring. This is documented across scientific literature, it's not a matter of debate.
Those with poor Theory of Mind cannot realize that "this is important to me" does not mean "this is important to everyone." (Childfree people can have poor Theory of Mind too, so that's not an attack on parents, put your pitchforks down.)
Since a parent's brain has been rewired to prioritize their offspring, those who don't prioritize any offspring don't seem to have any common ground with them. We're basically functioning in completely different realities based on how our brains are processing time and space. We don't share the same brain network. Our brains light up for different things, or at different strengths.
Childfree people aren't attached to your children. We do not have that neurological wiring because we didn't bond with your children that way. Your children are not equally important to us, even if we like you, or even if we like children as a general concept, or even if we like your children as individuals.
And that rewiring means some parents (not all) develop a miscalibrated threat detection system, where mild annoyance becomes a grievous affront and neutrality becomes a potential attack.
Someone not cooing at your child, or - dare I say it - being annoyed at your child screaming is not an evil person. They're not going to stab your child. They don't hate your child or you as a person. They don't hope all children die.
You just have a far more sensitive threat detection system than you did before. What is a very reasonable negative reaction to an unpleasant stimulus (children screaming, throwing things, running around, slamming a basketball for hours) has now been reinterpreted as a moral judgment because of the way your brain works now.
I don't like children. They annoy me. They are loud, unpredictable, repetitive, pushy, with poor boundaries. I understand that this is because of their developmental process and has nothing to do with their morality either. It's just two different people at two different life stages who don't like the way the other behaves.
This is a neutral thing. It is a preference. It says nothing about me as a person, or about you as a parent, or about anything. I don't hate children, and I don't want them to die, and I don't wish suffering on them. I want every child to be loved and cared for and provided with all the best opportunities in life ... and to be kept away from me. Because they annoy me.
The reason that annoyance has become so outsized is because I am constantly attacked and screamed at for something that is, in general, just a preference for how I like to spend my time and with whom I like to spend it. That has pushed me to like children less, and to want to spend less time around them, because even minor irritation is blown up into a massive debacle. I'm browbeat into glowing praise for children, and told they're "tiny humans" and that my reality is wrong because the parental rewiring overrides Theory of Mind.
I want you, whether you are a parent or not, to understand that just because your brain says something does not mean it is true. Someone disliking children is not a moral judgment on children as a class of people, and it does not require intervention, nagging, hatred, or insults. Someone ignoring your child in the grocery store is, frankly, the best possible reaction they can have, and it's bizarre to act like this is an affront.
Forcing people to like children makes them like children less, and makes you look like an asshole. Being pushy and universalizing parenthood as the ultimate good makes you look like an idiot. You're not doing anything valuable with your time.
And on the other hand, childfree people not liking children does not mean that we get to be assholes to them. We do not need to roll our eyes or scoff at children existing. We can ignore them; that is our right (I promise it is). We cannot go out of our way to be rude.
The world would just be a much better place if everyone accepted that their version of reality - including the preferences, desires, judgments, beliefs, opinions, and moral alignments - does not exactly synch up with everyone else's, and be okay with that.