Devil's advocate for why ontology is meaningless and vacuous.

[Gemini]

When was it established that morality inherently entails minimizing suffering? Or that acts of capriciousness and prejudice aren't moral?

That's a question about the target of moral theorizing. How is morality defined?  A normative definition stipulates that morality refers to any rational person's preference not to experience things like unnecessary suffering or acts of capriciousness and prejudice.

I think a descriptivist (morality refers to a code of conduct put forward by society, groups, or individuals for their own use) would have a harder time giving an objective answer to your question, which is why I think descriptivists tend toward subjectivism.

I'm with ANKA here.  My model, in which morality is an observed emergent property of replicating, evolving systems allows morality to be subjective and contextual.  Proving objectivity of morals (correspondence with a reality agreed to be tentative) is just as impossible as proving we have true access to that reality in the first place.  
Though someone empathizing with Gemini might have "true information about a part of reality."  They cannot know that that information is true.

We certainly seem to operate as though our capacity for empathy delivers reliable information about people. If you mean that we can't know this information is true 100% of the time, sure. But this is true of most everything we know.

We do, in good conscience, treat others with varying degrees of empathy.  I do not feel the same disquiet over the starving children in Africa as I do over my own starving children.  It is no coincidence that those who I feel most responsible for are those who are my closest relations.

This seems to be the result of having a concrete rather than abstract conceptualization of empathy. For someone with an abstract conceptualization of empathy, the starving children in Africa may cause the same disquiet you feel for your own starving children.

Gemini might find it good that others feel her pain, but is that pain good for the others?

Whether it's good for people to feel my pain is not the issue. The issue is that the capacity to empathize with me gives you objectively true information about the part of the universe that is me.