People often direct kids towards Windows and other GUI interfaces which the authors of the GUI claim are "simple enough for a 5-year old". What is the major difference1 between a 5-year old and an adult? Lack of experience. Which is no difference at all when it comes to comparing a computer illiterate adult and a 5-year old child!
So what they really mean is:
Simple enough for a 55-year old who having had the pressing job of (fill in your favourite non-technical occupation) hasn't had the time or inclination to learn about computers but now wants to play with the latest toy which everyone else has.
(He or she probably still doesn't really have the time or inclination to learn much about it.)
I strongly believe that Windows was aimed at white-collar folks of the above kind. And, this has been quite successful as a takeover-the-world strategy.
Now an interface designed with the above character in mind (and I am not saying that such an interfaces is not required) is certainly not appropriate for a 5-year old--who needs something attractive and challenging2.
My fear is that expecting the lethargy of a 55-year old will elicit exactly that from most 5-year olds---making for only a small minority of "computer geek kids" who will break out of this mold---thus perpetuating a cycle.
Computers are like air conditioners. Both stop working, if you open windows. -- Adam Heath