Of course they lost the ability to have wanted pregnancy which is a pretty serious loss for some people.
Right, but I suspect the parent implied that this could be a feature that many would seek out - basically the chemical equivalent of a vasectomy that can't be undone.
Some people, like me, really don't want kids. Taking control of it so that you're not relying on your partner is important as trust (that they haven't forgotten to use contraception or worse - deliberately not take it) isn't a rock-solid security policy. It's also not fair on females to be the only ones in charge of contraception for bare-skin sex.
Is the existence of injectable insulin scary just because someone could kill someone just by injecting them with it?
1975 isn't that long ago. If this technology is cheap and available, it will be abused.
What you're really trying to do is make out that somehow sterilisation is a special case of something with a potential negative use case, where if they can easily be used, they will be, without arguing why it's different from all the other things that meet that criteria.
That does not address jamesrcole's argument. He's not saying "it was always possible, therefore being easier is no different".
He's pointing out that there are worse bad things that are just as easy to do, yet they aren't considered scary.
You can't make an argument that the ease matters, because he's asking about things that are equally easy if not easier. Why is easy availability of such a drug different from easy availability of the knife/car/etc.?
You should be focused on access, control and any inappropriate uses. Not on whether the things being used exist or not.
One thing I've learned as I've collected laps-around-the-sun is that Present Me is a poor judge of what Future Me wants.
I find it much more interesting to ask why somebody wants no kids. That gives much more insight into the person's mind than when you try to persuade them with your own experiences and produces much better followup talk opportunities.
Anyway, I'm curious what you think it might be evolutionary advantageous. On the face of it, if others have less kids, that would seem advantageous to your own kids.