Biological determinism flatters the current elite -- "You're on top because you're inherently superior!" -- so it will always find an eager audience regardless of whether it is true. All the excess cheerleading makes it incredibly hard to assess.
I would have thought the exact opposite. Wouldn't the current elite rather believe that they are on top because they worked hard and earned their place? That way they can look down on the rest in good conscience while gutting welfare systems that only benefit those who "didn't" earn their own way.
Totes. You actually hear this exact argument from quite a few people who escaped poverty and become successful. They did it, so anyone can do it!
Arguments that the successful are morally superior will also find an eager audience. In contrast, arguments that successful are inherently inferior in any way are a hard sell.