> To use the overlap between one end of relativism and the other end of nihilism to then equate the two is taking it a big step too far.

This is somewhat fair, in that there is a supposed spectrum that I equated to one extreme. However, I think one end of relativism is sort of uninteresting because it's purely observational, and I think the middle ground is wishy-washy. Moderate meta-ethical relativism (as described in your link) postulates that there are some universal rules for morality. This is literally not relativist and I'm not convinced this can be a logically-consistent belief. Morals are relative, except when they're not?

It feels to me that moderate moral relativism stems from the "fear that relativism can slide into nihilism". This is not a logical approach, but an emotional one. If you start with the assumption that moral nihilism is bad, but you also don't believe in universal moral truths, you're left grasping for a middle ground where universal moral truths don't exist but also somehow they do.

This is essentially the same thing I was referring to when I said "the extent an atheist disagrees is decided entirely by how convincingly they can lie to themselves". If you don't like the logical outcome of your beliefs, you'll find yourself searching for a "moderate" version that is allows you to avoid confronting the reality of your views. Don't believe in universal morals but also can't stand the idea of no universal morals? Then define them as relative except when you squint just right.

If you actually hold the view that there are common universal morals that can be pulled from the commonalities of all disparate human morals, then you're a secret moral universalist. There's nothing actually relativist about "rules A, B, and C are universal, and then humans also add arbitrary rules D-Z depending on their culture". That's just squinting until "not universal" and "universal" look like the same thing and hiding it behind fuzzy language.

This is much like a theologist who attempts to reconcile the beliefs that God is omnipotent, omniscient, and omnibenevolent with the reality of human suffering by stating that we simply can't understand God's love and that's why he allows suffering. On the surface that might look like a logically consistent response, but it's a redefinition of "love" to mean something other that what humans would recognize as love. We "cannot understand" God's love, so God's love is by definition not human love, and so God's omnibenevolence is not human omnibenevolence. And what we've done is squint really hard at "not omnibenevolent" until it looks like "omnibenevolent" while ignoring the false equivalency between the two different loves being discussed.

> It seems to me like you're deliberately blurring the distinction between these schools of thought in order to take a pot shot at atheism.

You might assume so but you'd be wrong. My beliefs would probably be best categorized as "agnostic atheist". (If feeling clever I might call my self apagnostic, meaning "don't know and don't care".) I am a reluctant nihilist in that I don't see a logical way to believe that morals (or really anything else) have meaning in the face of an arbitrary, uncaring, and accidental universe, but all my instinct and intuition says otherwise.

I was not being facetious when I said I'd love to see an convincing argument that atheists don't have to be nihilists. I see that as the only logical outcome, but that doesn't mean I like it.