You have it backward. There's no absolute truth on what's optimal for what people use most. What's optimal is just what you were reinforcement-trained to feel when you were growing up as a child. That's it.

My wife says "30C" and knows exactly how that feels, while I struggle to find a reference point. I say "86F" and know exactly how that feels. Even though she prefers C, she can feel F slightly better than I feel C, as she moved to the US when she was in her teens. (Whereas I've spent my entire life in the US, outside of business and holiday travel.)