It depends on the point and the audience. If the point is complex enough, then you have to give up on conveying it to certain people. If the audience is smart enough, you reach past the lowest common denominator.

Indeed, the best way to write something that lasts for ages is to write something that ordinary people reject, bright people don't really understand, and the smart fall head over heels in love with. That's what keeps Plato in business. No one knows what he was saying exactly, but the really smart guys running the universe can't help but be charmed by it.

I wonder if 'the point is complex enough, then you have to give up on conveying it to certain people' is true.

That Feynman could explain fairly abstract physical concepts such that laypeople could understand them may imply that one needs to understand the 'complex point' better before trying to explain it.

Wittgenstein started one public lecture with a disclaimer to the effect, "This will not be one of those popular science lectures where you come out of the talk thinking you understand a topic that you understand nothing about."

With all due respect to Feynman, if at the end of his lectures lay people couldn't do the math behind the physics he described, they didn't really "understand" it. They understood a simplified picture of it that captured most of the important details in a really vivid way. But they were still missing something important.

That said, you're right. In the general case, we shouldn't allow ourselves the "out" of "oh, this is soooo complex that I can't speak clearly" without some pretty damn strong motivation. It's just that in this particular case, I didn't think the essay was especially jargon laden, so the OP's comment seemed misplaced. How much more simply can one explain that cities affect how you think?