Micro Transactions aren't new... they're just new to consoles. The reality is Destiny is an "Always "On" Game" it exist and operates on live servers.... servers cost money to operate, dlc takes cash to develop... So for Destiny to remain a profitable, and yes Bungie and Activision are companies formed for the primary objective of making profit, they have to have a more stable way of generating income. Thus you have two options; Micro Transactions or Subscription Fee! Destiny isn't like your Assassin's Creeds or your GTA 5, where the majority of the game is stored on your hard drive for you to access with or without friends. It is located on servers. So large initial sales will not, and can not generate enough income to fully support a games server support for a year, yet alone two years.