Whenever there’s a discussion about morality, it will always come down to one of two points: that morality is either subjective or objective, or absolute. Most likely, given the unreflective nature of the majority of people, some will argue that morality is, ultimately, subjective or relative. The reason that many will make this argument is because they look and see many different moral conclusions being drawn and will make such an assertion, however they will act as if they are drawing absolute moral conclusions.
For example, bigotry. People will claim that it is wrong to be bigoted in ones thoughts and actions. But if morality is subjective, the person making the claim that bigotry is wrong has no moral authority or justification to assert that in making such a claim that it has any bearing upon anyone else. However, someone who appeals to an absolute and transcendent standard, has sufficient moral authority to not only define what “bigotry” is but why it is immoral. Bigotry, for the subjectivist and relativist is merely a matter of taste in regards to personal preference. I may not like strawberry ice cream, but my not liking strawberry ice cream has no effect on anyone else. Same goes for bigotry, or robbery, or rape, my not liking those things doesn’t mean that there’s anything intrinsically wrong with them, or that they can have a meaningful definition, unless there is something to appeal to. In fact, if morality was indeed subjective, then the statement, “one ought not (fill in the blank)” could potentially be filled with anything. For instance, one ought not eat strawberry ice cream, now is morally equivalent to, one ought to eat their neighbor’s liver. Subjectivism ultimately renders moral categories meaningless because anything can be plugged into the blank. That is the reason why the loudest voices against racism, sexism, and classism come off as racist, sexist, and classist.
Unless there is an ultimate, transcendent, objective, and absolute standard that can define moral categories, there’s no grounds to call anything “immoral”. Everything else is arbitrary and subject to the whim of man.