I see it as a sexist comment if you're incredibly sensitive to any claim that men or women might have trivial motivations. It's unfortunate, but stereotypes don't just come into existence with precedent.
No, it's sexist if it's presuming that more women than men have trivial motivations or that those have more influence among women than men. Particularly when there are other, far less condescending and far more likely reasons for the gender skew in NYC.
I think you're right that this is not the reason for the gender skew, but I feel obligated to point out that the men might just take different actions in response to the trivial motivations.
