I'm going to point out several things.

1. Not all nerds and geek are boys and men or heterosexual. Neither are white. There are girls, women, and queer people among them (lots of queer nerds and geeks, by the way).

2. That means that some nerds and geeks date among themselves. There is even an specific app similar to tinder for nerds.

3. You assume that nerds can't be hot. But physical appearance has a lot to do with genetics. You can be beautiful and a geek (see cosplayers). You can be good at sports and a nerd. And some nerds are good at social skills and have no problem at all finding dates. And that is not because earning potential, is because being a nerd is about liking certain things.

All this to say: many nerds and geeks weren't celibates at highschool or later.

As for the empathy or docile thing, you have all kinds of personalities among nerds and geeks. You can even find bullies and resentful geeks and nerds. In fact, some of the worst bullies are like that because they feel resentful for the narrative that "girls doesn't value them for being nerds" and feel that they were owed that. So they bully the nerd girls saying things like "she is a fake nerd girl". Or "she is here only to meet guys". Which are lies.

Big bang theory was a fun TV show, but we should be aware that real life people are more complex and not unidimensional.