I know you're generalizing but I don't think vanity "monuments" is accurate of most techies' aspirations.
People just want FU money: comfort, security, and freedom. The "starting a succesful software based company" is a reasonable shorthand for FU money for techies because if programmers are going to get rich, they're not going to do it by striking oil in their backyard or acting as leads in Star Wars films. If people don't have fu money by the time they're 40-something, they question their current job, their previous life choices, and their future possibilities. People can get bummed out and even question their abilities -- aka wondering why they procrastinate and can't focus (e.g. "Damnit! I'm too distracted with social media!")
I think most programmers would be absolutely fine with being "not so famous" like Chris Hughes[1] with a net worth of $450 million instead of the more well-known Zuckerberg with $40 billion. Zuckerberg's face is on all the magazine covers but most programmers would be ok with no publicity and $450 million.
I don't think the percentage of techies with the ego to be the next Larry Ellison or Steve Jobs is that high. Maybe I'm wrong.