Most of the Crucible quests will help your team (Destiny)

by Kahzgul, Wednesday, October 07, 2015, 19:17 (3574 days ago) @ MacAddictXIV

Not all of them, but *most*. The Chaperone, for example, may be encouraging you to hang back and preserve your own life rather than rushing in, but having a high K/D ration is actively denying the enemy team points. You may not be earning massive points for your own team, but denying the enemy is just as valuable.

While many of the Crucible quests may get you out of your comfort zone (use Autorifles, play Salvage, etc), that's not you hurting your team so much as you learning new skills. I'll also add that none of the crucible quests ask you to kill people with a gun that does half the damage of a normal gun, or that paints a giant red arrow over your head when you use it or anything like that. I have, personally, gotten much better at the crucible as a result of having to adapt my play to the new quests' requests.