My realism might be weaker than yours but I think I was just confusing in part of the OP. Normative ethics isn't about explaining our intuitions (even though I say that, I misspoke). It is about what we should do. But we have no access to information about what we should do except through our ethical intuitions. There are cases where our intuitions don't supply answers and that is why it is a good idea to generalize and formalize our ethical intuitions so that they can be applied to tough cases.

Let me ask you, since you're a moral realist do you believe you have moral knowledge? If so, how did you get it?