The argument wasn't "Doing something bad is fine because others are", it's "You're trying to stop a bad thing happening by stopping some people upstream from doing something that's perfectly fine. That's going to be ineffective."
But you're right about me not putting a lot of thought. I didn't think this would need more arguing than that.
I still believe that tech is fundamentally neutral, and as such so is its development. Even if a developer intends to give it bad use, the use and development are separate questions.
There are others - not you - who will justify their own actions thusly: the technology existed, its better that the good guys (me - of course) should use it before the bad guys do.
In the space between both equivocations (yours and the other guy's), lies the potential for moral abuse.
Indeed, I think terming yourself in good vs bad as an we vs them terminology makes several biases go undiscovered that if you truly go for objectivity despite your sense of moral leaning is telling you.
But you're right about me not putting a lot of thought. I didn't think this would need more arguing than that.
I still believe that tech is fundamentally neutral, and as such so is its development. Even if a developer intends to give it bad use, the use and development are separate questions.