I think there is a lot of ego involved when we say we know how the world should or shouldn't function. Our perspectives are so limited and even the smartests among us have tiny brains. Whos to say that if you where in charge the world wouldn't even be worse than it is?
This reminds me of an awesome Futurama episode called "Godfellas". Bender gets to play God for awhile. It goes horribly. The take away from the episode is that God wants to move in ways that are not obvious at all that he is moving. If God where to directly intervene it would mess everything up. We are the ones that need to go out and make a differnce. Gods mode of action is to work through us, and not by constantly setting aside the laws of physics to fix every percieved wrong in the world.
Changing the human heart is a MUCH bigger miracle than parting of the Red Sea(or any other physical intervention of God).