Did you read his post at all? He knew what she was saying and addressed it clearly:

> What [AOC] meant was that it's impossible to get that rich without doing something bad — without cheating in some way... The reason [my founder's] startup was growing so fast was simply that users loved what she'd built. So she could feel from her own experience how wrong [AOC] was. She wasn't exploiting anyone. Exactly the opposite in fact. The reason her startup was growing so fast was that she and her cofounder had been working their asses off to make their users happy, and as a result the users had been telling their friends. And that gets you exponential growth.

In other words, this founder being on a trajectory toward billionaire status, through doing little but working to provide something of value to those willing to pay for it, belies the claim that you must be doing something unethical and cannot earn one's way to a billion dollars.