Unlike other ccg's during the deploy phase passing forfeits your ability to deploy later in the same phase, assuming the opponent doesn't pass also.
There's no reason to do what other ccg's do of course, but there's a good reason for a mechanic like this because it adds an element of bluffing to the game. Here, if i pass - my opponent gets free reign. Having initiaitve in the deploy is not so good.
Also, whats the point of having 7 planets in the game? Only the first 3 count for winning and only the first 3 will have their battle abilities trigger. The rest are only good for card draws and resources. There isn't much variety in those numbers across the planets (though it's good to gain extra resources/cards obviously!) so isn't that a waste having 7 cards during play? Their text will be meaningless.