App Design for Toddlers

Luke Wroblewski points out some app design constraints that are unique to apps designed to be used by toddlers. I wonder whether the designers of the apps he uses as examples did any usability testing with actual toddlers.

I'm not sure I agree with Luke's last point, though. He writes:

Many applications designed for kids don't check to see if an action is in progress before they start it anew. So when a child taps an image that plays a sounds then taps it again, the same sound will play over itself. Tap the image a few times and you have the same sound overlapping and echoing to the point of distortion.

It seems to me that this would be part of the fun (for the kid, not for the parents), rather than a problem to be fixed.