Humans are not Automatically Strategic (2010)
lesswrong.com
lesswrong.com
This is a version of "you, enlightened reader, are the special chosen few" - to me it reads no different in rationalist essays as when it gets pitched to me by multi-level marketers selling their get rich quick schemes. If you're familiar with reading bullshit such an appeal to the reader's vanity should immediately send up a few red flags, and it can completely detract from what would otherwise be a reasonable piece.
My final impression: https://xkcd.com/874/
I agree. General intelligence, to me, is defined as the ability to create a greater intelligence. An ability that's hypothesized for humans, but yet unproven. Therefore, on the cusp of general intelligence.
(The nuance is what Yudkowsky et al. tend to write about.)
second edit: "Can we actually change that en masse?" is the most interesting question.
Define "greater". And since your definition is recursive, define your base case.
I'll suggest that "intelligence" is about how much information you can extract from a given set of data. And since information theory says any given set of data only has a limited amount of information in it, this would imply that "intelligence" is not potentially unbounded but is on a scale of 0%-100%.