It was rare in Destiny before Trials. In some games you see it constantly, in others you don't, Destiny was one of the games where it just wasn't part of the core culture. It is still mainly in Trials and people who play Trials, when I play regular crucible it isn't that common. It makes sense since at its core Destiny is a cooperative game, so many people who play it are 'lets work together' types as opposed to 'I win, eat it'.