So? The primary thing stopping people from doing really really bad things is, and always has been, most people not wanting to do bad things.
It's never been difficult. Literally, right this second, you could grab a pen off your desk and pretty easy ram it into the neck of your nearest coworker. Killing's easy. You don't need some hyperintellect to tell you how to do it.
The reason you haven't rammed a pen into your coworker's neck is the same reason why most possible really bad things don't happen: People don't want to do them.
It’s interesting that most of the examples people making this argument give are high consequence, high difficulty (could you actually murder your coworker with a pen? I’m skeptical.) low kill count methodologies of violence.
We’re specifically talking about low difficulty, highly effective, high kill count methodologies of violence.
And yes, being able to kill a lot of people trivially, even with huge consequences is something people do. Most countries don’t let you run around with an armory as a result of that.