Marginal utility is not the same as rational self-interest.
Why don't you do both of us a favor and explain what Ayn Rand meant by rational self-interest. And by that, I mean what SHE meant and not what you make up as you go along. I suspect you don't really understand what she meant and yet you are trying to discredit what she meant (which you obviously can't do if you don't understand it).
Regarding religion, if you deny the harm religion has caused througout history, you are conveniently ignoring same seriously nasty sh-t. You might ask yourself why you ignore such things.
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