Why is there a rune and spell delay?

What is the significance of having a rune and spell delay? My little bro just started league and I'm playing with him and walking him through it... why does he have to wait before he can enjoy the entire game and all of its mechanics? It puts him at a distinct disadvantage in play. Is it to discourage smurfing or something? How is he supposed to learn mechanics when he doesn't unlock them until after he plays 30 to 50 games to reach level 7?