(I totally understand your point, but my understanding is that actually very little of medical significance happened to be learned from the human experimentation conducted by Nazi Germany and Imperial Japan during WWII, if that's what you're referring to. But for the sake of argument we can assume it did result in medical breakthroughs. Or if you're just referring to all the breakthroughs that occurred due to the pressure of the war, then that works, too.)

You're right, it's difficult to consider all technology as objectively neutral. If someone invents a device that lets any random teenager easily and cheaply release an aerosolized neurotoxin into a city center and kill thousands of people, it's hard to steelman the "it's the people, not the technology" argument in that case.

Philosophically, my post wasn't too rigorous or accurate. I think in the case of cryptocurrencies, though, there's enough of a balance of positive and negative that it's foolish to discard and vilify the entire concept, even if there are many uses (e.g. scams) that do deserve the critical reaction. If something has some positive utility to it, those always need to be kept in mind. Otherwise, all the politicians arguing in favor of banning encryption would have a much easier time, for example.

Let me try, though, because I think it's important.

Technology doesn't grow on trees. There are about two ways such a deadly device could be made available to a random teenager:

1. Accidental convergence of unrelated technologies. Somehow, it becomes cheap and easy to acquire a potent neurotoxin (an exotic animal or plant, perhaps?), tools to isolate, clarify and refine it (some toolkit from a chemistry lab?), a refillable spray can, a compressor, protective gear. A random teenager could then, technically, use all these to perform a chemical attack on a budget - if they knew how, and had a will to.

2. Turn-key solution. Somehow designs and makes widely available a device for cheaply release aerosolized neurotoxins.

In the first case, it's hard to blame any individual piece of technology involved. It boils down to the person willing to weaponize them, or one teaching others how to do it. Worth noting is that all the technologies mentioned (except maybe the neurotoxin itself) are already widely and cheaply available, and necessary know-how is part of high school chemistry curriculum - and I don't think anybody sees any real risk in this.

In the second case, the turn-key solution was explicitly designed with malicious intent - designed by someone who knew the end goal. Most likely commissioned by someone else, who also knew the end goal. Also made available to random teenagers by someone who knew what it is. That's at least three people with ill intent, without whom the technology would not exist (or it wouldn't be a threat). It seems to me that in this case, it's also the humans should be the center of focus.

With respect to real, instead of hypothetical, discussions about technological neutrality, I feel the constant focus on technologies and technologists in general is one big flock of red herrings - it exists to deflect the focus from the real problem, the people who commission and use these technologies with malicious intent.

Replace neurotoxin with chemical weapon and this is already a thing — I may be overestimating the industriousness of teenagers, but there is a toxic chemical a motivated teenager can make in two distinct ways using only things found in a normal kitchen.

Thankfully it was a rubbish chemical weapon even when deployed militarily in WW1, but it is a possibility.