It's the same reason that if Oprah took her billions to try and solve some global problem with her husband Stedman, many mentions of the work they were doing would not mention Stedman.
One is a famous individual who built up an obscene fortune, and the other person is married to them. And despite how involved their partner is deploying that wealth for the good of the world, people are just not going to mention the less famous one who didn't build up the fortune as often.
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.
Bill Gates also regularly gives speeches. I checked and Melinda doesn’t have any on youtube since 2013.
So Bill is very much the public face of the foundation, even though Melinda is equally active and her name is in its name.
Not the only reason, but worth pointing out a prominent benign one.
For instance, a parallel example is how ycombinator is often mentioned as being founded by Paul Graham, and Jessica Livingstone is left out. Why? Partly sexism of course. But Paul also was the public face of YC with his essays.
And we have evidence it’s not just sexism, because YC had four founders
> by Paul Graham, Jessica Livingston, Trevor Blackwell, and Robert Tappan Morris.
I think the second two are even less well known than Jessica Livingstone, and this correlates with how much public writing and speaking she’s done as the face of YC and about startups.
(There’s a whole other discussion to be had about whether women are chased out of the public sphere, but this comment is long enough)
What "ism" is the reason reason Warren Buffett is more famous than Charlie Munger?
> He is best known for creating the Morris worm in 1988,[3] considered the first computer worm on the Internet.[4]