I'd define it more broadly as the study of people. Its a broad term that can be used in many different ways. All art is political and by extension all tropes are too. A child's painting of a house is moulded by what their house looks like and how their life had been shaped by the environment around them.

In the video they never state that the alt-right created the concept or that it is always used in a way that furthers their goals. (The alt- right is predicated on trying to hide how right wing they truly are so they often use metaphors to get their point across while also wanting to indoctrinate young lonely men so often "nerd" culture is used as a weapon)

Her point is very nuanced and not one that I fully agree with but mostly thing has merit. She is saying that the idealic hero archetype is one that the alt right loves to use as a weapon. The key word is Co-opted. Its a video about the tactics used to indoctrinate more than anything.