its overpowered when you flick the left trigger and fire and it kills someone without you ever looking straight at them. It's overpowered because it throws off weapon balance by letting something with extremely high damage AND range also be used in the one area where it shouldn't be effective in. (You wouldn't be ok if I discovered a way to hit someone across entire maps with a shotgun and kill them.).
Don't deny this just because you have a hard on for abusing the exploit that these guys never had the backbone to correctly remove.