I think a better (less cynical) way of interpreting that is this:

Jobs which require a belief to perform sincerely, select people who hold that belief sincerely.

This principle should undo a lot of cynicism. Yes, eg., people in marketing often "really believe" their efforts are a net-positive, and no it isn't often, "mere cynicism" on their part.

Rather, what has happened, is that most who view marketing cynically, do not take a job in it.

We often misidentify this process of selecting for sincerity as a psychological-reality in those who are selected. Marketers "make money through cynical means" whilst sincerely believing they don't.

I've met marketers and product people of both kinds. The cynical ones seemed to half hate their jobs, and justify the SOP clickbait as keeping up with the negative sum game they have to play. The less cynical ones seemed to be kind of detached from externalities, and described their marketing copy as "standard marketing puffery" to justify it to legal.

It took seemingly forever, but eventually we (mostly) got HN commenters to stop saying "LOL Betteridge's law of headlines!", along with a Wikipedia link as if we hadn't heard it a hundred times before, to every article. Hopefully we can get to that point with this stupid quote too.

I guess I don't read HN enough that I don't recall ever seeing it here, but a quick Google search confirms your impression: this quote has been super prolific on the site. I hope I at least reached a few readers who hadn't seen it before.

I guess the next quote to axe will be Gell-Mann Amnesia. But hey, they all wouldn't be repeated so often if they weren't painfully accurate.