I'd like to add a bit of relevant rule "Control of Attachment : If an investigator attaches a player card to an encounter card, he or she retains control of the attachment." (Location is an encounter card.) ...that gets overridden because Pitchfork explicitly said "lose control of Pitchfork". (It is also on Hatchet.)
Without this "lose control" effect, it would magically disappeared from the ground if you (the owner and also the controller) gets eliminated before someone grab it and take control.
Location attachments like Map the Area, Makeshift Trap, Breach the Door, ... you would be unable to left a legacy for your friends to continue working on it after you get defeated. But you can with Pitchfork.
That said, this is a fun multiplayer weapon that net you more damage than its setup cost by utilizing actions of other investigators taking turn after you (and their accuracy), as long as you successfully pass the baton by landing a successful hit. They would lose whatever hand assets they have, so this is viable for a flex with empty Flashlight looking to transition anyway, or 3 Mystic that is currently using Arcane.
The accuracy bonus is just +1 , I think it is important that the Pitchfork owner having commits ready to "teach" others how to farm. (Hank conveniently and thematically has 5 to farm without help, and should be able to keep commit cards for others.) It is very likely that you are still standing with someone trying out the fork after you. I imagine a huge in-class icons like Dauntless Spirit or Last Chance can be a good enabler to squeeze more 3 damages in one Investigation Phase. Suddenly, it might looks possible to deal about 3 damage in one round regardless of actual role of other investigators.
It gets messier if you are attacking an enemy engaged on other investigator and you would like them to continue the attack, they'd not be able to pick up without taking AoO, so you might need an another Engage to free them and end your turn. (And risk of getting skewered for 3 damage but that's part of the fun...)