You don't have to though. In sto people can get keys on the exchange too, spending no real money.
Also, the items from lockboxes are sold on the exchange, so again, there's no need to spend real money. I keep seeing so many people say how easy it is to earn credits in this game, so buying lockbox items from the GTN should be easy enough.
the odds on main items are so low, the other payment system is nothing than a charade possibly in
place just to aid with loophole in laws.
the other area of concern though is if this is being done to benefit the game and us etc etc, then why don't these company's release information on the winning odds if it was a casino it would be a requirement and a gester of good faith