I never see anyone using the AN-94.
Yes it is supportive. If half your team is pinned by a tank, and your mortars kill it, how is that not supportive? If a teammate is having a hard time with a guy, and you pop him and helps your teammate kill him, how is that not supportive? It's the players that make it that way, not the class it's self.
2 for me, 100 posts per page FTW!
teammate having a hard time killing a guy would have had an easier time if you would have been next to him throwing motion mines or 1 shotting him at close range with your sniper rifle. You can do a dozen more supporting actions if you are with your teammates or near a flag than sniping from a bush on the side of the map.