You objectvists are such starry-eyed dreamers! Far from seeing things as they are, you see the world as some giant confection, where one's sweet tooth is satiated whatever one does.
One theory about moral rules, religious sanctions, and laws, is that we are all tempted to do things which, in fact, are NOT in our long term self interest. For example, according to anthropologist Marvin Harris, sacred Hindu cows are in fact a greater economic et alive than dead. Alive, they provide fuel and power. Dead, they provide a bit of meat. The Hindu prohibition against eating cows (Harris argues) is necessary because in times of famine, when people get hungry, they are likely to ignore their enlightened self-interest in favor of a medium-rare filet mignon.
I'm not sure that Harris is right (in fact, I think he's wrong on this particular issue), but I think his point is worth talking about. The tobacco companies may have been better off in the long run being honest, but in the short term, heads would have rolled.
Perhaps the "super-natural" (religious) ethos is simply a metaphor for a ethos based on cultural rules, ped down for generations, and necessary to protect us from our own tunnel vision.