Now if they use it to kill good guys, then it's a problem that needs to be solved.
I would have thought most people are somewhere in between.
Is an enemy combatant with a weapon a bad guy? How about an unarmed enemy combatant? How about an enemy combatant with just a knife, or a rudimentary club? How about an armed civilian who might be an enemy combatant?
Is a bank robber a bad guy? If so, do they deserve to die? How about a white-collar fraudster? How about someone running from the police? How about a mentally ill person running from the police?
This stuff is never clear cut. It's why we have courts and military tribunals. If you can't think beyond 'good guys' and 'bad guys', I don't respect your opinion.
Pay attention to the facts behind the curtain.
My government did enough stupid things for me to not want them to have sophisticated military toys.
Debatable, but regardless - do you think the reason US government have not killed Snowden is the lack of "sophisticated military toys"?
Also, my government did enough stupid things (like killing innocent people in war zones by mistake) for me to want them to have more intelligent weapons.
It's a hard problem, and most glib solutions are, well, just that, glib. Centralized agreements become increasingly difficult as the number of entities increase, for instance, even before we account for scenarios like this where the reward for defection increases proportionally to the number of other participants in the disarmament.
This is also ignoring those cases where there isn't even disagreement; in the real world, for instance, while you can quibble about the exact lines it seems to be the case that the Chinese accept and approve of levels of "invasive government" (to use a Western spin on the idea; I don't know what they would call it exactly) that Magna Carta-descended countries would consider abhorrent, making coordination even harder. (Meanwhile, they consider our lack of coordination or whathaveyou, if not "abhorrent", at the very least "sub-optimal", and possible dangerously socially negligent. As I'm using English here and, like I said, I don't know what they'd call it exactly, I can't help a bit of a Western spin here, but I acknowledge the flip side.)
No argument here, having a strong bully in the room is good for you when he is on your side.
Frankly the broad majority of people in the US benefit materially in some way from their existence in ways that they might not even be fully aware of.
I am not arguing this is a good thing, but I think it's a reality. Military power abroad means wealth accumulation at home.