Ever get a nice high pedigree pet with slots for all the talents you could ever want? And then you go to train it, and it learns something oddball that neither of the parent pets ever learned? And then you're basically out 40,000 gold and have to wait 12 hours. Then you try to hatch again and something else goes wrong?
If you hatch, you know what I'm talking about.
I would pay good crowns for an elixir that would untrain the talents my pet learned, and randomize its talents so that it would learn a different set of talents upon re-training. It wouldn't be an iron-clad guarantee that I would get the best talents next time, but it would be nice to rescue a failed pet instead of hatching 10 more that also fail.