I can see that. But if death is birth into the next life, and being born too early in this life can really mess you up, then couldn't dying too early mess you up for the after life? Just a thought. And if you kill thus person, they won't learn their lesson. They will proceed into the next life, whatever that may be, with the same thinking they have now. Especially since their thoughts before they die us just kind of 1"I'm dying" and not "if only i wouldn't have..."
The curse would take the form of something seemingly unrelated. So that car he/she gets hit by or the cancer he/she develops, will be the only reason for that persons death in their mind. So it won't really fix the problem, just put it off, or possibly make it worse if the soul gets added to the universal energy; then the corruption will get added to everything also.
Its better to correct the problem than it is to blow it up and live in the radiation.