I agree with this. If the "religious sense" is removed I can understand why some may think evil is merely a "human concept" but the question I have is where does this "exceptional kind of bad" come from? Honestly, growing up I had no concept of this kind of "evil" until it was foisted upon me from the outside and I still find it difficult to understand how people have such thoughts, let alone act on them.
I like the thought that we should "be good to each other and to ourselves" but without an objective standard of what is good how are we to know what the good is that we should be doing to each other?
There is an objective good and an objective bad. It's just that the waking mind can't always discern what is good from what is bad, because we don't immediately face the consequences. But those consequences always take root in the subconscious.