People don't want to "branch out" because Bungie keeps nerfing other weapons and making them less consistent options for the casual Destiny player. Generally, people want to stick with gear that they find reliable as opposed to something that may put them at a disadvantage. This isn't about "getting good", this is about how the current meta discourages variety and encourages sticking to weapons that have been least affected by Bungie's poor balancing. You need to sit down and stop trying to tell people how to play the game when you're not even fully aware of the real problem at hand.