Even so much as a survey is hard to properly reproduce, definitely more than a day's worth of work if you need to go out and find a random pool of surveyees. Opening up a spreadsheet in your favorite software sounds fairly approachable by comparison, assuming it has no fancy university-level mathematics in it.
Whether it is fun to talk to people for a survey vs. sit through pages of arithmetic is a whole other question, though.
His point was that, if you take the trouble to disagree with him (you being another academic, a reporter, etc), then you should also actually grapple with the numbers. Which I think is valid.
I don’t want to sound cynical, and this certainly isn’t ideal from a “cultivate a vibe of intellectual humility and curiosity” perspective, but is it a surprise to anyone but the author that laypeople didn’t take to a thorough critique of his work?