Look at it this way. The taken king as a whole new separate game. Why does COD come out with new maps and a new game every year. It gets stale playing the same game, using the same weapons. Camping in the same corner. Why is there 15 final fantasies? Time moves on. You can still play vanilla destiny any time with all the exotics you have accumulated but if you want to play more destiny and find some more weapons and armor that will be just as fun to play with you have to try different strikes and raids and new gear. I think it keeps things fresh. After a while though it's all the same, you will eventually find another game that is more fun for you to play and that's it. Why is there 5 gta's? I mean things need to change, that's true in life and in games. The past can always be revisited though.