Agreed Smollet, I am actually looking forward to a harpoon fix in the far far future more than the upcoming coop mode.
In it's current state it is widely accepted as being entirely useless, this has been acknowledged by muse and they themselves have labelled it as broken. New players are drawn to it because it sounds interesting and end up assembling ineffective builds.
If it's broken and totally useless, if it's capabilities are misleading and damaging to inexperienced players only through their ignorance, why leave it in the game? Take it out and bring it back when it works.