"It's the concept that society is the way it is because a process of darwinian selection has settled on the arrangement and it is dangerous to wantonly mess with this complex system."

An economist sees a $100 bill on the sidewalk. He neglects to pick it up because it can't possibly be real. If it were, an efficient market dictates that somebody would already have picked it up. A five year old follows behind, picks it up, and exclaims "Look ma, I just found $100." The economist turns around and says, "See? I was right."

Just because Darwinian selection gives better results than any individual decision does not absolve you from making individual decisions. It works because of the presence of mutations: take away the mutations, and evolution ceases to give useful results. You see the same problem in finance: the market is efficient only to the extent that people do not believe it is efficient, because once people start believing that it's efficient, they'll invest in index funds and nobody will actually scout out the information needed to drive good stocks higher and bad stocks lower.

In short, I think that culture is a complex, self-regulating system, and that alone is why it should be messed with.