I think the tweet is implying that 99% of the "leaders" and "brilliant successes" in our "creative, innovative, disruptive" industry are in fact a coterie of not-very-remarkable, yet very-privileged, 30-somethings whose achievements rest on a combination of luck and having made the most soulless and conformist career decisions available.
People can do whatever they want, but if they're truly "highly capable" maybe they should try something a little more challenging than following the herd?
I hold no ill will against all of these people getting rich this way. Let's just not pretend like they're innovators, though.