The Moral Intuition of the Nationalists

So much of what we think about the world is based essentially on unprovable intuition. It's as true to say that murder is wrong as it is to say that the Earth orbits the sun, right? If you're going to dismiss one because there's no way to sort of resolve the fundamental conflict to someone who disagrees with you, that's true of like all epistemology. Why can't we just do the same thing for ethics in saying that, yeah, we have this unproofable intuition that sort of my well-being is good for me or like maximization of positive experience is a good thing?