The question was "Why isn't she mentioned?" He did not ask "Would it be apt to mention her?" "Should you also mention Melinda when referring to the Bill and Melinda Gates foundation?" The answers is yes to both of these questions. She is an impressive person who has accomplished much in her life.

He did this (I assume) to imply the reason she was not mentioned was because she was a woman and not because of the large and obvious disparity in fame.