"does not automatically mean one is more privileged than those who choose to work for startups,"
It does in a way. Founders eating ramen, working long, odd hours, for an idea that may not pay off at all; Who can walk away from a startup and brush it off as experience. An employee doesn't get that opportunity. An employee also doesn't take the risk. They may never have the opportunity to take these kinds of risks.
I have no idea, but a statistical correlation does not justify the blanket characterization made by the article, where "risk-taker" is essentially held as a synonym for "privileged".
It diminishes the accomplishments of entrepreneurs, and the sacrifices they've made. If they only have large equity stakes in the companies they founded because they're "privileged" it casts them as undeserving of the wealth they acquired.
Isn't it self-evident? It harms their standing and reputation, in being cast as in possession of wealth they are not morally entitled to. It's defamation.