There is that stereotype of a nerd with the high pants and pocket protector and that kind of thing. That can sustain comedy for maybe a movie - hence the 'Revenge of the Nerds' franchise - but not for hopefully years on the air. It's a sight gag, not a story.
This quote highlights how stereotypes, while effective as quick comedy devices, lack depth and lasting storytelling power. It suggests that characters reduced to a single exaggerated trait might be amusing in brief segments or films, but they struggle to sustain audience interest over long periods. This reflects the importance of developing well-rounded characters that transcend stereotypes to tell more meaningful and engaging stories, both in television and other media formats.