You seem to be under the impression that there is but a sole optimal IQ. This seems unlikely, when one thinks about the radically varying conditions lived by humans at, say, the Arctic Circle and the Equator, particularly before the rise of globalism.
Gould's ideas have not stood the test of time, and it is now understood that he committed the fraud and abuse of which he accused others. This is why he has been disowned by his own colleagues, something that never happened to Einstein.
The average IQ produced by natural selection depends on the environment. There is no ideal level of intelligence apart from environment. If the Earth had a uniform climate, terrain, and so on from pole to pole, this presumably would not be the case.
Human personality contains any number of traits that can be measured. To pretend that pyschometrics does not exist is the equivalent of refusing to look through Galileo's telescope.
When you say that some of the best hacker and hustlers that you know come from unimpressive backgrounds, does "some" mean "most" or "a few" or "hardly any"?