When appropriate measures have massively failed, what are the alternatives? Vigilante actions are one option, as is "watch the whole thing burn down", and probably an infinite variety of stuff in the middle and along different axes. What's your preferred option?
edit: also, it's not quite "may [do] something worse". Insecure IoT things are used as botnets. Frequently. It's not a hypothetical threat at all, it's just a question of scale / frequency.
So, vigilantees concerned about damage to innocent people keep breaking into the windows, stealing the guns, unloading them, and tossing them into landfills. I'd be like: "Stop putting your guns in front of the windows. Be a responsible gun owner." Enough broken windows and stolen guns might incentivize them to do that.
So, in a way, yes. I do. So do lots of people when they go to urgent care rather than the ER, knowing that the ER could bankrupt them, and they'd rather risk the delay. I don't have numbers off the top of my head, but I don't think it's as uncommon as you seem to think it is.
You are priced per body part based on your income. Your health is most certainly defined in dollars.
I daresay that this situation even applies to "most people", or at least a very sizeable proportion of the global workforce.
It's IMO somewhat comparable to culling high-risk farm animals to prevent widespread disease outbreaks.
> Where do you have legal authority to do a vigilante culling of your neighbor’s herd, because you decided something about them merited it?
I am not making the argument that this is legally defensible. You can by definition not have legal authority to engage in vigilantism. It's from an ethical and practical perspective that I draw the analogy.
On the matter of legality, the difference you point out applies, but also goes both ways. There is no legal framework around "culling" insecure devices, and very little regulation.
Where do you have legal authority to do a vigilante culling of your neighbor’s herd, because you decided something about them merited it?