Tactical Advantage - You make use of the terrain, creating a tactical advantage that provides cover and funnels aggressors to the tip of your spear.
I’m thinking use of the ability would create a stone outcropping around the Hunter in roughly the shape of the Greek letter Omega, breaking line of sight from ranged attacks and providing collision against would-be melee attackers except through the opening.
I think this would be an extremely versatile form of group utility that the spec is very much in need of. This could be used to break LoS from casters, which I imagine Prot Warriors would greatly appreciate, as a barrier from melee attackers which would have useful applications across all forms of play, as a means of securing a kill or node cap, or as a way to block a healer’s LoS on his allies.