This doesn't negate his point. The criticism is that too many people are going into "industries" that do not create any wealth. The fact that he also got well paid in finance demonstrates that the current system rewards finance.

https://qph.fs.quoracdn.net/main-qimg-dc8c42a6725776dfc54ed8...

https://upload.wikimedia.org/wikipedia/commons/9/92/NYUGDPFi...

Correlation/causation yeah, but you can't have more people doing nothing of value and more middle class.