Not being from the US I don't fully grasp what these things are (is Columbia Ivy League?) but all knowing this does for me is make me conclude these qualifications don't seem to mean very much and may even be anti-correlated with intelligence - the author seems to be very sure she's making some deep social comment with this piece, but she isn't.
I'm not exactly an expert on Stoicism, but even I knew it's not about pointlessly imposing suffering on yourself: it's about caring about what you can change or improve and accepting the rest.
Please keep in mind the SV populations sensationalized in articles such as this represent maybe 1-2% of the people in SV. Everyone else is simply trying to support their families and raise their kids the best they know how - pretty much exactly what the rest of America does.
A lot of people are criticizing it here. There is a bit of condescension in the tone of the criticism. It was not hard to search for the author (https://en.wikipedia.org/wiki/Nellie_Bowles) and find that she graduated magna cum laude from Columbia and was a Fulbright Fellow. That certainly doesn't mean she's correct about anything, but I think that casual dismissal of the article is a bit lazy.
On a personal basis, it seems worth looking at how certain intellectual trends propagate through certain SV populations. Neotrophics/microdosing, Burning Man, and Stoicism are examples off the top of my head. In particular, it feels like the general point of the "Why are they attracted to Stoicism" section isn't completely incorrect. It is definitely a topic worthy of a longer form exploration.