The OP is mostly talking about image, not reality. What image do tech founders choose to project.
OPs timeline is somewhat off. They posit a golden era for the 1980s-2007 but that’s not right. Tech CEOs have often been hard-charging salespeople and businessmen. Look at early Wired magazines and there was much celebration of random rich guys in suits, as much as the nerdy tech creators. This was the “suit/hacker” dichotomy.
Google was the company that really exploded that paradigm, from their rise to prominence circa 2002 or so, to their IPO and post-IPO halo, around 2005-2007.
Now the nerds didn’t need the suits. They would run their own company.
They were shockingly wealthy and powerful but it was made to seem as a kind of distraction from their true nature. They marketed their own virtue and renunciation, both to the public, and to their own staff. Their business model rejected the previous search engine paradigm (backroom deals and paying for placement) in favor of a new one (complex math to produce the best results). They told the public and their staff the famous “don’t be evil”, and also “focus on the user and all else follows”. There was even a pronouncement that Google would never do such tawdriness as horoscopes.
The theme was that nerdiness was a kind of incorruptibility because a nerd was honest, unconcerned with social status, and unworldly. Let them into your life and they’ll make it all better. Larry Page and Sergey Brin cultivated that image, holding internal and external events where they made themselves look ever nerdier than they actually are, even wearing lab coats.
Now, this didn’t last and was never true. Soon after the IPO, Larry and Sergey bought themselves not just a corporate jet, but a commercial airliner. They justified it as something that was “good for the world” because they could use it to get entire teams of NGO workers on missions of mercy. It actually became a party plane, as far as I know.