They may actually be. Although mostly not in the way you're talking about, but there is something to be said for the dispersing of power. If one or two players have a power no one else has, there's more temptation to use it. If it's widely distributed, it seems reasonable that any one actor would be less likely to wield that power. (I admit I'm being a bit hand-wavy here on what I mean by "power" but bear with me. It's kind of an abstract point).
To argue against myself, I'd say that the difference between weapons and AI is that AI is more general. It's not just a killing machine. In fact, I hope that killing represents the minority of its use cases.
So do I generally speaking, but with a caveat... I think that having multiple (eg, more than 1 or 2) nuclear powers is likely a Good Thing (given that the tech exists at all). The whole MAD principle seems very likely to be one reason the world has yet to descend into nuclear war. The main reason I prefer nuclear non-proliferation though, isn't because I genuinely expect something like a US/Russia nuclear war, it's more the possibility of terrorists or non-state actors getting their hands on a nuke.
It's interesting though, because these various analogies between guns, nukes and AI's don't necessarily hold up. I was about to say a lot more, but on second thought, I want to think about this more.
Unfortunately during the cold war, neither side could really rely on the other to just chill out for a couple of days. So now we can deliver hundreds (thousands?) anywhere in the world in about 45 minutes.