"Most people don't want to murder innocents" isn't reassuring. It only takes one lunatic. And there's a lot of lunatics out there.

Then the proper solution is to create fewer lunatics: provide better mental health support, good social safety nets, and a more egalitarian society.

Well yes, but that's a utopian idea that can never be fully realised. You can't fix them all. There'll always be some number of crazy, broken, malevolent psychos out there. If you don't think this is true then you need to meet more people.

We need to minimise the damage they can cause, and that means preventing them from using slaughterbots.

> Why bother with children at that point?

the premise is that the person doing it is very mentally ill. the question, "why would they do that when they could do something else that makes more sense?", doesn't make a lot of sense itself under the premise.

If a person is very ill mentally then there are already many ways to kill people in numbers, some of which ways are much more accessible than slaughterbots.

It's the barrier to implementation that I find concerning and the lack of defensive innovation just as much of a concern.