I like this idea, AND the corrolary, that such curses can be countered/removed. I recommend by quest or 'civilization goal'. Consider the Quest for the Holy Grail. The king is cursed, which curses the land. All the knights go a-questing.
I look at Death Curse as a trust fund, mana AND essence invested. So you're less awesome before your end in order to be awesome AT your end. Besides, who ISN'T planning on going down in MP laying land-wasting devastation upon your enemy? This is just another way of doing it.
Also, I think it helps to BALANCE the way I've seen most multiplayer games go. One player gets an edge, and slowly builds on that edge, wiping out a player. He now has 2X resourcea, and the next player falls that much faster. He now has 3X resources, and so on.
Further, it encourages MP games NOT to last for 18-26 hours of 'footsie', ending in massive armies with maxed-out tech. You want to wipe out those enemy channelers BEFORE they can set up their death-curse.