Earlier quoted context omitted.
It’s related to the trope that non-rich people are more ethical than rich people, or nerds would treat women better than jocks. Confusing lack of opportunity to engage in certain behavior for lack of propensity.
That's an interesting point since in practice, athletic ("jock") women tend to be more common than nerdy women to begin with. Women being into tech or science (stereotypical "nerdy" pursuits) is something that tends to happen more in lower-income countries, which suggests a large self-interest or incentive component, while the opposite is true for athletic women. Perhaps the proper counterpart of the "nerd" among wom…
This is it.
Nerdy women are in fiber arts, fandom (especially generative fandom), etc. Nerdy women definitely exist, they just tend to take their penchant for nerd/obsessive/systems thinking to more 'appropriately female' areas. (For example, things like indie perfume houses, or my obsession with the mechanics of bra manufacturing and fitting). They also tend to pick apart relationships instead of objects: This is why female fandom is so dominated by tropes and boxes to shove characters into. They like the organization and clean categories just like male nerds do, they just apply them to different domains.
They also usually have a different but related stereotype. We're pathetic shut in cat ladies instead of pimply nerds. It's also not usually considered a problem until we hit ~25 (or whatever age the culture at the time considers a woman ready for motherhood) since a shy, obsessive, escapist woman who doesn't want to engage with people can make a fine wife/gf. Most of the grief is directed at us for not caring about our appearance enough more than anything else.