The way the game is designed, with its archetype system, the game cannot be balanced. Since the beginning of destiny people were still figuring out the differences between all the guns and archetypes and their strenghts and weaknesses. But quickly after that the meta system began. Destiny never had balance amongst all the weapons. The meta switched from autos to handcannons to pulses then to scouts. It's just the game's design. Bungie decides what should guns should be popular for a few months.