Because this crucible is garbage compared to established fps titles. It's also impossible to balance crucible due to a lack of uniformity. Everybody has different guns with different perks and everyone wears different armor with different perks. Then you have multiple subclasses and a myriad of perks there, so balance in a game like this is impossible. That, in my opinion, is why people don't pvp in destiny but will in other titles. It doesn't feel fair and that makes it hard for a lot of players to have any fun playing it