The fact that people could Ascend just about anything, and reroll Legendary weapons. Combined, it means people just use one of the same handful of weapons and whatever gear they can get max light on the fastest. And Done. Therefore, less diversity. I'm sure when they said "Let's let them ascend purple weapons" they assumed that would increase diversity as people would use some weapon that they like but others hated. I mean there are hundreds of Legendary weapons out there. Instead it became "Instruction Manual - Get Weapon A, Reroll until you get perks X/Y/Z, win" Over and over. Min-Max to roll the best possible weapon. Now most Warlocks look the same, and a large % run with one of the same 4 or 5 legendary primaries