Oh, hmm. I see now that we were interpreting Popper differently, and I may have been wrong.

Notice that the questions he gives for essentialists are actually interesting questions, they're just imprecisely phrased, e.g. "what is matter?" These questions were asked before we'd decided matter was atoms. They were valid questions and serious scientists treated them. Now these questions are silly because we've already solved them and moved on to deeper questions ...

If Popper did mean to exclude that kind of inquiry, then I agree with you that he was misguided.

In that case, it sounds like you would agree with the rest of Anatoly's comment, just not the Popper quote. Is that right?