It is a wicked symbol. Just that Doomsday is, ultimately, a one-off villain... who was very
effective that one time.
See, I really liked the Death of Superman, even though it was essentially a 150 or so page mindless punch-up, it was done in a manner that kept amping up the tension, and beautifully reflected the exhaustion of our hero, and the near-hopelessness of his cause. If he hadn't
died (or "died") it would have been terrible. No other story with Doomsday will match that, or, even theoretically, can match that. Unlike Luthor or Brainiac, there isn't a possible ultimate Doomsday story waiting around the corner.
But there can't
be such a thing as a single-use intellectual property in a serial genre.