I bet you didn't know that baby ducks are not only incredibly cute and destined for Extreme Tastiness, but they also bounce!
They don't bounce much, it's true, but they bounce far better than, eg, baby horses would. And if we were to genetically engineer ducks to be made of steel, then while they might bounce much better (especially if dropped onto a nice hard surface like concrete) they wouldn't taste as nice. I think the current Bouncy Duck design is a good compromise.
The impatient might like to fast-forward to about 40 seconds into this video.