While some points are rather weak, others are indeed legitamite. Why bother with charity under atheism? With no ultimate meaning life is ultimately pointless and thus is very much a reason for depression. Why not descend into murder and sociopathy under atheism? There's nothing to prohibit it, and under a legal system runned by mankind as the ultimate authority people are capable of getting away with any crime. The fact that many atheist's object to such behavior is indeed a contradiction for atheists when they subscribe to a belief that perfectly allows for it and thus no ground is given for people to object about anything.