Because despite what their religions told them, people still surely fell in love, experienced passion! Im not talking about biological urges, I am talking about the need to feel whole, Desire itself. The idea that some moments can make you feel like life is beautiful, moments where you feel you can die right then and it would all be worth it.
In general you are suddenly being prescriptive rather than descriptive, which implicitly seems to show you agree with what I am saying about belief, but you simply think that humans should change fundamentally. Which is fine, but it is itself a belief you have that you contextualize your life with!
