Why? Seriously -- why? If there is no God, why do they care about any of the things on their list? If you are stronger than anyone around you, why not just take from everyone else? If you see a woman you think is good looking, why not rape her? There is no reason to live a "good" life if you can be happier living a "bad" life if there is no external morality in the universe.
Its like Woody Allen's "Crimes and Misdemeanors." The only thing that stops someone from murdering a person who is causing them trouble is their own feelings of guilt, and eventually those feelings subside.
If you truly are an atheist, this list is complete BS. Its a vestige and legacy of humanism, which in and of itself is simply an attempt to reconcile their Godless world to Christian morality. Atheists don't want to face the reality that without external morality --without God -- there is no reason to adhere to anything on their list.
Isn’t what you mention the whole point of what Nietzsche was trying to tackle?
-— If there is no God, why do they care about any of the things on their list? -—
Peter Kreeft gave the answer in one word: “Sex.”
It’s the part of the Natural Law that restricts their impulses the most. Atheists don’t want to be robbed or murdered. But they don’t want anyone telling them who they can schtup. (Of course, they don’t want anyone cheating on them, but they don’t think that far ahead.)
That’s what it boils down to.
And if you notice, that’s what atheists and modernists get the most bent out of shape about.