Right. The standard of right and wrong, good and evil, holds regardless of what men think, and whether they call good evil or evil good.I get that. But the question with taking the Lord's name in vain is not whether it is offensive to humans or not, but does it use the name of God in a way that is not needed.
However, in terms of human interaction, we do have to deal with the taking of offense, as Rippon2 seemed to with "God forbid." If my memory is still intact, I can't say I remember anyone ever before referring to this as taking God's name in vain (though this might be my limited experience). 8 centuries of Christian Bible translators seem not to have noticed it, though they may be wrong. I don't know the philosophy of new translations that avoid it, though I'd guess they are trying to be more word-for-word than idiom for idiom. The older translators seemed to be going for a sort of "optimal equivalence," translating a Greek idiom with what they saw as a parallel English idiom.