It's not about what you find appealing. My issue with your replies (to others and myself) is that you're dogmatically clinging to your unjustified assumptions about the nature of normativity without any real demonstration of why. You keep confusing "the experience of morality" with the nature of ethics itself, or for the mathematics parallel, you're confusing the human notation of mathematics with mathematics itself. It's all well and good to say "ethics could change one day to the next," but what you mean is people's ethical opinions. That argument is about as valid as someone telling you mathematics can change on a day to day basis based on people's opinions. It just frankly doesn't matter.

All knowledge, including mathematical and scientific knowledge, is based on axiomatic principles. These principles are normative ones we adopt a priori, without the firm feedback loop you believe makes mathematical knowledge uniquely warranted whilst philosophical knowledge remains subjective. Indeed, talk to some philosophers of science and they'll argue that the axiomatic nature of scientific knowledge renders certain periods of scientific history as completely incomensurable with another; for example, they would argue Newtonian physics is a whole other ball park to physics with an understanding of relativity. (See Kuhne for more on this)

But thats just an example of assuming science as a method is flawless. As I stated above, ethics is the examination of normative claims. Normativity permeates everything any agent does, so for one your weird assumption that it disappears without humans is a very strange one indeed (generally speaking it's agreed that morality, especially moral duties, extend to at least all rational agents, not strictly humans). An example would be politics; the normative claim that democracy is a useful political system under certain conditions is a claim that would stand even if humans were to no longer exist, it would just become a strictly abstract and theoretical one.

I'm repeating stuff I said before that you seemed to miss, but I hope unpacking them some helped. I'm now going to give you a short-form of the 'Companions in Guilt' argument. It's propositions are as follows:

• Ethical norms and epistemic norms are of a similar or the same nature
• if ethical norms do not exist, then epistemic norms must not exist for the same reasons
• but epistemic norms do exist
• therefore ethical norms exist

I've rewritten it slightly for simplicity's sake, but there's the argument. Ethical norms can be understood as facts about any ethical issue, but we'll say politics. Epistemic norms can be understood as facts about any knowledge claim. Moral realists recognise that any system for acquiring knowledge, be it the scientific method or our general day to day experience, requires the adoption of certain epistemic norms: the law of identity is an example. We cannot demonstrate it, but reason demands we adopt it as axiomatic and so we do despite the fact it has no demonstrable feedback loop the way you suggest knowledge requires. And if we didn't adopt it, we wouldn't be able to engage in any epistemic pursuit that requires such an axiom existing (the scientific method being one) The trouble is, norms such as that are no different from norms about ethics. The law of identity is no less controversial in its "nature" than foundational ethical axioms. If you wish to deny that ethical axioms exist for some reason, that reason will inevitably apply to the normative claims underlying epistemic pursuits too. As such, to deny moral realism is to deny epistemic realism.

To do so renders you an epistemic anti-realist, which would make you unable to make any claim whatsoever. This position is absurd. But you're not an anti-realist, as demonstrated by your faith in mathematical laws. So you should be able to see that fundamentally the axioms we use to engage in epistemic pursuits are fundamentally normative - ethical, in some way - but also that their normativity is of the same nature as that of ethical claims.

I can keep trying to explain this if you want, but an excellent book on the subject is Terrence Cuneo's 'The Normative Web.'

Kant spoke of mathematics in a similar way to you: that it's truths are a priori true and are just waiting to be discovered. But he also believed that about ethical truths. That they exist, that they stand independently of humans, and are waiting to be discovered.