I mean I like to hold my cards closer to my vest than this, but if we're just going right at it:

(1) He wasn't a practicing scientist.

(2) He wasn't fired for making scientific claims, but rather for saying things like "I'm pessimistic about Africa".

(3) He didn't do any research in behavioral genetics, psychometrics, or molecular genetics; his authority in the discussion was "famous science guy".

(4) He lost an honorary and, later, an emeritus position, in which his role was not "scientist" but rather "spokesperson for a scientific organization". I wouldn't want him for a spokesperson either, any more than I'd want Ibram X. Kendi or, maybe closer to the mark, Elijah Mohammed as my spokesperson.

James Watson was closer to Donald Sterling than to Galileo.