If the Bounty Manager knew that the project is scam and still promoted it than they deserve a negative trust.
But if they didn't knew about that, they are no different from bounty participants as they get paid to advertise.
I agree. The real deal here is how do we differentiate those; who's the all-knowing Bounty Manager or who's not. Although, the OP is somehow right that Bounty Manager do some examination and interrogation, at least, to make sure that a project is not a scam.