This is the difference between good bounty managers and ordinary ones. A good one will hire a person, for a small fee, who will check all social network participants for the quality of the content and the quality of the services provided.
A good project does not need useless marketing; it needs a precise and high-quality presentation of itself through bounty hunters.
Is there really a way to check the quality of the work of the bounty hunter if their only task is to like or share in social media? I don't think that there is a need for that quality check. What they need is to limit their bounty participants to at least give them enough opportunity to receive more rewards.
I think he is talking about completing the tasks and also some campaigns have task like they need to create own posts about the project they were promoting in the required number of characters so it could also fall into the quality.