Please tell us more about your inside information on the psychology of Bill and Melinda Gates

I have none. Just an opinion that given my posts downvote counts suggests that I shouldn't share.

Ayn Rand did not invent the term "altruism"?

Neither did the Effective Altruism people. But Ayn Rand's books have sold a lot and are read by influential people, so I'll use her definition until I have a reason not to.