I've been speaking with some more educated friends of mine who have told me that I hold a moral subjectivist worldview. They asked me a series of questions, promoting me to tell them that I believe morality is entirely a matter of expressing one's own feelings rather than a matter of facts.

For example, a friend of mine and I agree that attacking another human and taking their property can be at least sometimes "moral". My rationale for this stems from what I've been told is an egoist viewpoint, that it may serve my own interests to do such a thing and therefore is something that I should do. He approached it from a utilitarian point of view, arguing that sometimes it is necessary to do what seem like bad things for "the greater good". I don't think calling this action "moral" is anything more than each of us stating that we approve of it, just as my friend who comes at this from a place influenced by divine command theory believes that it's immoral "because God said so". I don't think that's anything more than her expressing disapproval of the action stemming from the teachings of her faith.

Am I understanding moral subjectivism correctly from what you're seeing so far? What are the arguments for or against this viewpoint?