[1] https://slatestarcodex.com/2015/12/17/should-ai-be-open/
There won't be a moment before and after the invention of the AI. There is the creeping offloading of responsibilities to more and more automated systems we understand less and less. Already now these systems take decisions that we can only understand in hindsight if at all. We cannot approach them in a deterministic way like we're used to.
These guys are just full of themselves to think they will have it and others won't. And also that they will be able to control it.
Even if we actually had the capability to make a human level intelligent AI that was trivially able to be commaned to go genocidal, and it fits in an average desktop PC it would not be a good comparison to nuclear weapons at all. It would lack any MAD and have far more applications than large radioactive explosions or large power generating reactors.
Its a weak argument. The bad guys are still using it, you are just ensuring that only the well-funded groups have it.