The whole thing (and indeed the book) is well worth reading, but the "unkind summary" TL;DR is: When new evidence doesn't fit the old theories, most of the current batch of scientists stick with theories that no longer match the evidence. But, over time, the old scientists die, and the new scientists who replace them accept new theories that match the evidence.

Maybe culture is so different now that his studies are no longer applicable to currently-working scientists. Maybe not. I honestly think it would be pretty interesting to repeat the study over the last 50 years and see if the results are the same.