Quoting from the OP:

"Darwin first proposed this notion about choosy females and randy males, clearly without ever studying primates in depth because primate females are notoriously sexually promiscuous."

"Darwin’s theory was purportedly scientifically confirmed in 1947 by Angus Bateman’s study on fruit flies. Bateman’s conclusions still loom large in the popular imagination, even though they have been scientifically discredited time and again because of flawed methodology resulting in biased results. The problems with his studies were glaring but they told a story that fed into a predominant cultural narrative, and his work kept being passed along as correct."

"If Bateman’s conclusions about sex roles and sexual selection, and science and popular culture’s embrace of it, read like a suspiciously wistful and retroactive justification narrative in which males are active doers, competing and winning and losing and striving and eager to spread their seed and then bolt, as passive, coy, choosy females rain on their collective parade and try to get them to be true while expecting never to pay for their own drinks, that’s because it is. As real gains in equality put women in charge of their reproduction, their earnings, and their destinies more generally in the last decades of the twentieth century, Bateman’s ideas would be periodically reactivated like a virus by anxiety about social change. Wherever and whenever women were independent and in little need of being protected and provided for, the notion that they should passively choose the one most powerful male to safeguard and provision them, and all that it implied about femaleness versus maleness, would be aggressively promulgated by a range of scientists, writers, and politicians whose interests it served."

TL:DR - evolutionary psychology types and self styled "alpha males" talk about this 100 days thing all of the time. Here's one of the comments on the story from another woman who hears this all the time as well.