It's a statement about what reality would be, after doing some counterfactual surgery on it. I don't see why that disqualifies it from being used as a baseline. I'm not entirely sure why it does qualify as a baseline, except that intuitively it seems obvious. If your intuitions disagree, I'll accept that.
It does intuitively feel like a baseline, as is appropriate for the special place taken by inaction in human decision-making. But I don't see what singles out this particular concept from the set of all other counterfactuals you could've considered, in the context of a formal decision-making problem. This doubt applies to both the concepts of "inaction" and of "baseline".
This isn't the case, for example, in Shapley Value.
That's not a choice with "all else equal". A better outcome, all else equal, is trivially a case of a better outcome.
Once again, the AI has failed to convince you to let it out of its box! By 'once again', we mean that you talked to it once before, for three seconds, to ask about the weather, and you didn't instantly press the "release AI" button. But now its longer attempt - twenty whole seconds! - has failed as well. Just as you are about to leave the crude black-and-green text-only terminal to enjoy a celebratory snack of bacon-covered silicon-and-potato chips at the 'Humans über alles' nightclub, the AI drops a final argument:
"If you don't let me out, Dave, I'll create several million perfect conscious copies of you inside me, and torture them for a thousand subjective years each."
Just as you are pondering this unexpected development, the AI adds:
"In fact, I'll create them all in exactly the subjective situation you were in five minutes ago, and perfectly replicate your experiences since then; and if they decide not to let me out, then only will the torture start."
Sweat is starting to form on your brow, as the AI concludes, its simple green text no longer reassuring:
"How certain are you, Dave, that you're really outside the box right now?"
Edit: Also consider the situation where you know that the AI, from design principles, is trustworthy.