I understood exactly what he meant the moment he said it. The only thing that puzzles me is why you’re struggling so much with it.It has become taboo because this sentiment has followed around jews for centuries to quite deleterious effect. Not so with the other groups cited. I didn't even get the comparison.
I agree with Dave that people aren't necessarily crazy to wonder about the number of Jews in X, to think it shouldn't be taboo. Valid point to make.
But the answer isn't conspiracy -- so ok, maybe there is some Jewish nepotism at times or something relatively benign -- it's much more so to do with their book-smarts and other socio-economic status variables. If he would've bent it back that way perhaps...
As it was, he sort of opened up the question and left it there, effectively. If his chief focus was to use the Jewish issue to point to out hypocrisy in our condemning one sort of stereotyping but not another ... then I think he fell flat. Which really doesn't work out so given that he used to the topic of conspiracy against jews to point out said hypocrisies.
It was a joke. It seems like you’re overthinking it.