I could not disagree more! That "do what you want to as long as it does not harm others" is the closest thing to a moral philosophy that most people have these days is exactly the problem with society, if you ask me. My generation has absorbed the letter of the flower children while completely missing the spirit. The point of "do your own thing" and "love is all you need" was certainly not "as long as you're not hurting anybody you can do no wrong". It was more like, "We must all learn to tolerate each other" and, "Let there be peace on earth." A civil rights/Vietnam war protest thing. As many immoral elements as there were in that generation as well, it was eons ahead of us. Krauss, being older, should know better. But I don't think that is what he means. He's just honestly demonstrating for us--more honestly, in fact, than most atheists do, so kudos to him actually--what happens when you're stuck forcibly shoehorning everything into a strictly materialistic mindframe due to holding an atheistic view of morality.
So maybe it is true that this must have been the highlight of the debate, now that I think of it.