Because he lives in the real universe where "good in life" is a fact about people rather than about the Awesomon, the fundamental particle of goodness.

Well, suppose someone went out and asked a bunch of old people what they had done that they loved, and what they wished they'd changed. What journal would they publish their findings in?

And again, it's not just that knowing more about what people love and regret is useful, or that going out and doing science requires solving relevant harder-to-communicate issues - it's also that being interested enough to ask the question is a good sign. A person who actually goes out and collects data is someone who is trying to learn new things, push the boundaries of human knowledge. It makes me willing to bet on the average experimental psychologist over the average philosopher who's interested in well-being.