Jeremy Stangroom

That's a stronger reaction than the ephemeral joy at reading about a disliked person's death.

Another example: disappointed that Milošević died before he could be convicted of war crimes. Also a stronger reaction.

Compared to those reactions (which I believe are very normal), the fleeting verbal "grave dancing" seems rather trivial.

And you can say that those reactions, even if normal, are morally problematic, but what if the edifice of morality stands on such feelings?

I.e., what if such emotions - both positive and negative - are necessary for formation of moral standards?

The propensity to condemn seems fundamental to moral sentiments. And "grave dancing" is an expression of that propensity.

It's one of our least attractive characteristics, even if, as you suggest, it underpins the construction of moral frameworks.

Yes, I agree with that. It's another way of saying that enormous harm and suffering was caused by pursuit of moral purity.