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.