I do agree that grave dancing is pretty retarded (it just shows everyone how vindictive and petty you are because the person being grave danced is dead and they can no longer defend themselves anymore).
But Kiwi Farms actually likes grave dancing, it's just that they don't like it when it happens to them. They don't really care that it happens to other people they don't like (such as the case of that underaged troon that killed themselves a few months ago where afterwards some really sick-minded trolls and A-Logs thought it would be funny to grave dance on a dead minor).
If you want to condemn grave dancing then that's fine but be consistent about this rather than cherry picking your own morality. Grave dancing is either immoral or it isn't, you can't have it both ways.