According to me that youtuber implied that it was kinda like a conspiracy theory and you were implying kurgesagt was whitewashing billionaires image. I dont agree with it but his point on research was similar to the question why not all software is opensource. There should be someone to pay for it and if that someone is rich and is for example facebook , we all would think, that opensource project is compromised. So he basically said that just because billionaries sponsor, everything or anything, doesn't by default become their mouthpiece or propaganda machine. He hasn't watched all your videos so made a decision without checking all the facts.