If you play black ops 3, you'll notice they've implemented cod points which is basically the silver of destiny. If you haven't, they're used to buy supply drops in game. Now, you're probably thinking, "Oh, it's just Activision pushing out micro transactions again." They are, but you don't need to buy them because you can get a separate currency in game from just playing that can be used to get these supply drops. So why isn't there something like this in destiny? Because Bungie, not Activision, wants it that way so they can make more of a profit.