Because it's all RNG. Nothing is really earned. It's all just luck. Sure you can say you did a lot of grinding for your stuff. Doing night falls and raids every week. But really, it still comes down to luck. I've played with people who've gotten an exotic from both raids and the night fall all in one day. While others didn't even get any for several weeks. Nothing is ever really earned in a game based on RNG. It's all about the roll of the dice. So I'm totally fine with having to get new gear. Keeps the game fresh for me. I get bored after a while of using the same top tier gear. I for one need change to stay interested. Now I know not everyone likes change. Especially if they feel as tho they are being forced into it. But when a sequel comes out to a video game isn't it kind of the same deal? Yes this is just DLC but the concept it still the same.