Objective morality as a proper basic belief

[Mister Agenda]

I had hoped at least the first one would be obvious, since I named it: Appeal to emotion and appeal to consequences. And maybe appeal to incredulity.
Plus it is factually untrue that that people who believe morality is entirely subjective can't condemn Nazi war crimes. They can and usually do.

As a side note, the Nazis, who largely subscribed to OM, did not seem to often consider their atrocities to be crimes.

In my view I don't think that either side, can make a definitive argument for the conclusion.   However I don't think that it is incorrect, to appeal to the consequences of the logical conclusion of a view (especially when adherents to that view don't behave in a manner inconsistent with that belief). This is part of what is meant, by appealing to an innate sense concerning objective morality.  Now I would agree, that just because we don't like the consequences or it gives a negative emotional reaction, that we cannot logically conclude that it is either true or false.   This would be the fallacy that you speak of.  But I find a dissonance between what is said that subjective moralist believe, and how they behave.  Requiring you to accept the consequences of said belief is not illogical or incoherent.  Your example about condemning the Nazis is apropos.

It is a pickle. I have had a similar initial visceral reaction to a friend going with 'morality is subjective', however my cognitive dissonance at the idea doesn't mean it's wrong or that I get to try to back him into a corner regarding endorsing atrocities if he doesn't accept that doing so is an implication of his position.

I can't comment intelligently on the Nazis position on OM (perhaps they had varying views as the label doesn't require any particular holding that I know of) Also, an incorrect belief, doesn't change whether the topic at hand, is objective or subjective by nature (regardless of the subjects belief about it's nature).  Here I normally ask the question though.   What is it based on the subject that makes it wrong?   Is it merely against your tastes or preferences?  With a different subject thus a different basis, isn't their position equally valid; subjectively?

I think there is a repetitive attempt to make those that hold that morality is subjective as having a morality equivalent to having a preference for a particular kind of ice cream. I think that's a false equivalence, because moral choices are drastically more consequential. It's an attempt to demean the position rather than refute it, like saying team sports hold little value because it's just people chasing balls. Morality can be subjective, but involve life-and-death consequences...and virtually everyone subjectively does not want to be murdered or tortured.

Now I find that most people behave as if there is a moral realism.  That morals are objective, and actually honorable or wrong, regardless of the subject, time, or culture.  That there is an innate sense, that some things are definitely wrong, outside of the subject (culture), and anything within them.  Subjective is not the default position (neither is objective).  And as I said, I don't think either can make a strong argument that it is one way or the other. However I find that the behavior of people shows more about what they really believe, rather than any statements or what they think the believe.   It's similar to the post modern notion held by some, of objective truth or that of philosophical nihilism.  In reality, they quickly betray what they say it is they believe.

Do they really say they believe that all actions are morally equal? Just because they don't conform to how you think a moral subjectivist 'must' behave doesn't mean they aren't a moral subjectivist. None of those things you say people have an innate sense about is universal; and if it was an innate sense, it would be universal. There could reasonably be defective individuals who didn't have that 'sense', but there wouldn't be cultural differences over whether genocide is okay.

I'm a moral realist, btw, but I get that if you don't find the axiom that what is good for people is good self-evident, you're not going to agree with my moral reasoning, though you may coincidentally agree with my moral conclusions. When someone says their morality is grounded on a deity's pronouncements, they're just basing their morality on a different axiom than I do. I don't find that one self-evident at all.