Evidenced by the almost dozen players that use them heavily?
It's not used a lot because they don't fit into the usual playstyle of most people, which is being able to solo mobs of enemies (they still fail at it, but they think they have a chance if the take 2h/the favourite poelarms). Honestly, when I'm meleeing, the worst enemies are the ones backed up by pike/bill and so forth. They are AWESOME support wepons, the problem is that people don't wanna play support.