For the Golden Age Chronicles, that may be true, but now that they're branching into Silver Age Chronicles, where the reproduction is not as costly, I wouldn't say that's a given necessarily.


"As for contentment, that is a myth.  Give a man everything he wishes and he will be unhappy, because he didn't wish for more; give him more, and he will die of his worries.  Only a turtle, asleep on a sunny log, knows contentment!"
-Merlin to Prince Valiant

            Hal Foster 3-7-43