Before you can plot your intricate masterworks of machination and power, you need a good solid foundation in game mechanics. I can't even begin to list all the master plots I have seen fail miserably, and often quite comically and embarassingly, because the mastermind behind them had a fundamental misunderstanding of the game mechanics. Not only that, but these academies give new players a good sense of involvement and activity that can be beneficial in retaining them.
Besides, who says they can't learn politics while learning the mechanics? It's not like it's a one-or-the-other proposition.
