Watson may have gone over the line from genius to whacko, and if so, he joins a long line of geniuses in many fields.

However, his genius is not up for debate as the author claims, at least not among most people who understand his scientific contributions.

Rosalind Franklin deserved more acknowledgment than Watson and Crick gave her for her X-ray defraction work that was important to their discovery, but if there are lots of people who think Watson stole the DNA discovery from her, those "lots of people" are people who don't understand the discovery path of DNA. Perhaps they have read polemic books written by other people who similarly don't understand the path.

Watson may have become disgusting. The same can be said of Michael Jackson and Ludwig Wittgenstein. But Jackson was a genius at performing and Wittgenstein was a genius at philosophy. You can attack them and Watson for what makes them disgusting without gratuitously and inaccurately denigrating the evidence of their genius.