they were perceived to be incapable of rational thought.

Yes this is how the eugenics people justified their beliefs and actions. I suspect that Bill Gates holds a similar mind set just going by some of his public presentations.
I saw a small clip of Gates included in a David Ike video. I tracked down another video of Gates wearing the same clothing with the same background but not that same words being uttered. I asked for the original from one party and asked the other if they had cut a segment out, nether replied. But it seems plausible that it could well have been a deep fake.Its hard to know anything with certainty these days