I'd like to tie up some of the things you said in your first and second posts in this thread.

You started with:

I don't understand the quote. Under what definition of "nihilistic" does it make sense?

and I responded with a link to the definition of moral nihilism in wikipedia, saying moral nihilism is the label for the belief that there are no objective moral truths or falsehoods.

You responded with

It seems very obvious and uncontroversial to me that morality is not objective.

When you say something is "uncontroversial," that means that, barring some class of people too stupid or whacky to be bothered with, people competent to have an opinion agree with you that it is obvious that morality is not objective.

In response to that I briefly summarized moral realism and linked to its wikipedia entry. By this I intended to show that the community of people who believed morality to be objective was competent and obvious enough to have a simple label on their belief, with that label cited and explained widely by (it seems) everybody who bothers to summarize moral philosophy.

I did NOT mean to suggest that moral realism is obvious or that I believe it or that the negation of moral realism is obvious or that I believe that. I DID mean to suggest that it IS controversial, meaning literally that there are moral realists who controvert ("speak against") nihilists and nihilists who speak against moral realists.

From there we go in to the weeds, or at least I do. First, I muddied the waters by talking about a particular example which I thought clarified some issues but which seems to clarify nothing, so it is not worth even mentioning again.

But the other sort of amazing thing to me is you keep asking me to defiine moral realism. What do you want me to do, copy the first few paragraphs from the wikipedia article? I'm not going to do a better job than they do. If you think the definition is dopey or meaningless or whatever, then oh well. I have nothing to add.

A belief that morality is subjective is controversial by any straightforward meaning of that word, nothing else I have said is as relevant to anything else you have said as that.