... and cook with bacon grease, despite the fact that science has shown that it's not good for me. And I'm even a (lapsed) scientist!
Sam Harris has written a book on how science can determine moral values.
I'm sure it can. The question is: Will anyone listen? Knowledgeable people thought the Facebook Revolution in Egypt would lead to enlightened self-rule, too. That didn't turn out so well. People don't always behave in ways that are rational to the academic world.
Moral codes are only as good as their enforcement mechanisms. That goes for Greeks avoiding taxes and Mafia goons breaking the knees of people who don't repay loans. I'm sure Mr. Harris has argued coherently and has whiteboards full of flow chart diagrams, but unless he's found a way for the powers that be to agree with him, he's just another guy in a coffee shop pounding away on his laptop generating moral codes for himself and a few thousand readers. If he does it in the wrong country, he's just another guy in prison.