Capture the King

Our group is a grass-roots movement dedicated to the notion that a Chess Game is over when you actually Capture the King. We don't believe in stopping just short of ultimate victory, we go all the way. We also don't believe in restrictions on movement of the King. The King is the King, he can go wherever he wants. If he risks capture by moving onto an attacked square, that's his business. So, we don't say 'check', or 'checkmate'. We know the game is over when our King is captured. You can start playing 'Capture the King' by finishing your games using the Analysis Board (uncheck 'Enforce Legal Moves'), and you're on your way! Think about Castling. Currently the rule states that you can't Castle through check. Why not? If we describe Castling 'through check' from the Kings perspective, it would sound like this: "I'm skipping over two squares...fun...Whoa, under attack....OK, made it through. Phew, close one!" Why is this not allowed?