Why not? Because it's wrong. I can sense that it's wrong, even if I have no other evidence, and the fact that nearly everyone else agrees is pretty good confirmation. That's not proof, I suppose, but I'm willing to behave as if I had proof because there is not enough disconfirmatory information.

I believe in the moon because I can see the moon, I trust my eyes, and everyone else seems to agree. I would continue to believe in the absence of any other evidence. If I couldn't see the moon I might not believe, and that would also be rational. I can see, however, and I trust my moral sense as my as I trust any other sensory organ. Just as with a sociopath, I think you would have a hard time proving the existence of a specific lunar crater to a blind person, but the fact that she lacks the capability to see it isn't evidence that it isn't there. People that can see can see it, and that will have to be enough.