Thank you for your feedback. I have a couple of replies that will possibly spark further discussion.
(1) I may not have made it clear, but Dr. Kay certainly believes that children should explore and interact with their environment directly as well. A computer isn't (as he pointed out) a very good way to learn how to play baseball.
(2) Most computer languages and software does not encourage playing and exploration. I was a math teacher 20 years ago when PC's were being introduced to schools. We watched students play with LOGO and used it to encourage exploration in geometry. At the time, other math software for these grade levels seemed to be little more than high tech flash cards.