That's just a steaming pile of horseshit. I'm sorry to be so blunt, but I've been in this world for a while now, and nothing infuriates me more than when entrepreneurs try to delude employees (particularly younger employees) into working for far below market in exchange for promises of fairy farts and equity dreams.
In a city where a one-bedroom apartment costs >$2,000 a month, $100k isn't a "fat" paycheck. It's right about average. And even if you choose to work below market, the <1% equity stake that most funded startups are going to offer you won't make it worth the opportunity cost in anything less than the most exceptional outcome. You say you're working for $60k a year in San Francisco? Yeah, I hope you're getting a founder-level equity, because you're living with roommates and eating ramen.
I suppose the only plus side to this kind of nonsense is that any developer worth her salt will be poached within months by any one of the dozens of local startups that are looking for engineers and willing to pay market wages.
Don't fall for it, kids: you deserve to be fairly paid, and get some equity.