The Trespasser should have been an exotic quest. A quest which required the use of sidearms. This would have given people the incentive to try out a good sidearm in crucible. You see.... I only started using a sidearm recently because I got the Thorn quest... And the most consistent way of getting void kills in the crucible was to use a void sidearm, which I would always have ammo for. I bought one from the Vanguard vendor at Tower and it turned out to be a beast of a weapon (3 shot to the head at mid-range). Sidearms were brought into this game later than any other weapon archetype and due to the fact that shotguns fill their role for most people more consistently, they're very rarely used. I personally use my sidearm as a finisher. When I'm fighting more than one guy sometimes I won't have the magazine capacity in my primary to take them both out, so switching to my sidearm mid-fight is perfect for getting in quick damage. Not to mention, you always spawn with special ammo when you use a sidearm.