Destiny is built like an MMO, where you grow a character with levels, then at max level you use gear to increase in power beyond max level. In World of Warcraft it's your Item Level. Here it's your Light Level. They also created raids to function just like MMOs where it'll take multiple full clears to get everything you want. For instance, my raid team has 2 30s because not everyone has all the raid gear they need despite clearing VoG every week since release. This is just what every other MMO does; sometimes it takes month for that weapon or helmet to drop that makes your character stronger. Same here. Bungie make not want to call this an MMO because it's not really that massive, but it's built on the design bones of games like World of Warcraft.