GP must have assumed that people who've procreated have enough social awareness to know that if they really want their daughter to date nerds, they have to forbid her from even hanging out with that kind of guy--you never know when they're going to hack a bank, or make some kind of dangerous robot with lasers and rocket engines on it.
I'm a nerd. My sister's a choreographer. My parents encouraged my sister to date my nerdy friends. It generally had the opposite effect.