It’s that she didn’t accept the reasoning behind that number enough to really believe it. She added a discount factor based on fallacious reasoning around “if it were that easy, it’d be here already”.
Just to clarify: There was no such discount factor that changed the median estimate of “human brain compute”. Instead, this discount factor was applied to go from “human brain compute estimate” to “human-brain-compute-informed estimate of the compute-cost of training TAI with current algorithms” — adjusting for how our current algorithm seem to be worse than those used to run the human brain. (As you mention and agree with, although I infer that you expect algorithmic progress to be faster than Ajeya did at the time.) The most relevant section is here.
Ok, gotcha.
Just to clarify: There was no such discount factor that changed the median estimate of “human brain compute”. Instead, this discount factor was applied to go from “human brain compute estimate” to “human-brain-compute-informed estimate of the compute-cost of training TAI with current algorithms” — adjusting for how our current algorithm seem to be worse than those used to run the human brain. (As you mention and agree with, although I infer that you expect algorithmic progress to be faster than Ajeya did at the time.) The most relevant section is here.