It's a good question.

I was an overweight, sensitive, nerdy, smart kid. Growing up in the 80s/90s, I totally get the nerds vs jock divide (that I think was REALLY exaggerated on TV). I didn't play sports, I played computers games before they were cool, etc.

I TOTALLY get the Penny Arcade mindset.

The difference is, I fucking grew up. They are still nothing but man-babies in adult bodies who have never grown out of the puerile "us vs them" mindset. Thank god I had a based dad AND mom who both kept me grounded and kept me reading. I got in shape in my 20s. I started lifting in my 30s. Today in my 40s, I am more "pro-masculinity" than I've ever been before.

That doesn't mean I repudiate who I was as a kid. That doesn't mean I love meathead dumbass jocks. No, fuck those guys. Masculinity is Marcus Aurelius. Masculinity is Odysseus (not the Nolan one lol) who moved heavens and earth for his people and his family. Someone mentioned Tolkien--Masculinity is Tolkien who spent years crafting a moral, ethical, and Christian work, from tales he made up for his children. Masculinity is Tianamen square tank guy who died to protect others. Masculinity is strength, both mental and physical, taking responsibility for you and your family, and having the willpower to be you--to stand up to the crowd.

I would say during the hippie era. That was when pop culture began to look down upon the traditional man as an outdated, bigoted, racist warhawk. Of course with that, traditional masculine things like knowing how to fix your car when it broke down, or how to run a farm, or how to engineer systems were lumped in with the old world, since those were competitive and not the new age of "kumbaya we will all live together in our multiracial paradise".

Then came sitcoms where the man of the house was portrayed as a bumbling incompetent while the wife was portrayed as intelligent and responsible. You had shows before that like I Love Lucy where they had female characters, but they didn't put down the male ones. That changed with shows like the Simpsons or King of Queens.

The death knell was the institutional enforcement of eliminating bullying in school.

The bigger of a societal misfit you were the more you were punished back in the day, in the 2000s that changed and the degenerate weirdos started being celebrated. All part of the LGBTQUIABCDEFG cult worship that gained power in that same time.

It's not popular to say, but it probably has more to do with the divide between (((white))) people who are "book-smart" but have asthma and are adverse to physical exertion and White people who are athletic, charismatic, and more practically minded.

Edit: Think about the (((Hollywood))) movies and how the bookish underdogs are always the good guys that get their revenge on the good-looking jocks who bully them because they are "different".

IQ correlates with height.

I think a big factor is the "victims are morally better" mindset that started around the 60s. Before that, no one cared about refugees, for example, because they were, obviously, losers. Then the peaceniks started squawking about "war crimes" and "humanitarian aid" in the context of the people who lost deserving to be given consideration just because they lost.

Translated to our school culture, there are plenty of athletic, tall, charismatic men at all the top tier universities (well before they started the practice of ignoring standards to recruit meatheads) competing at the highest levels of sport, who had the intelligence and ability to be physicists. But we started only caring about the losers, going so far as to pretend that only the geeks and nerds were intelligent because that would mean "everybody is equal but some people excel at different things". See also: "women are physically weaker but are better at intellectual pursuits/the arts/dealing with people" and other myths.

It was basically the point that Liberalism turned necrotic.