So Ender's Shadow shows that the teachers running the game behind the scenes were playing a much deeper game, one designed to bring about the insights that Ender developed. That further, it was important that Ender developed them on his own so that he realize, he can never depend on doctrine handed down from the past, and so develop something from a fresh start.

Besides, Ender's Game is simply the setup for Speaker of the Dead, a much more interesting book.

To be fair. I read Ender's Game multiple times when I was younger. I have not yet read it again now that I have a better understanding of Sun Tzu's Art of War and the John Boyd biographies. I have no idea what I'd find if I read it again.