You have to know, bounty hunter get paid by the project's coins/token. And there's coin/token allocation for bounty hunter for every project they do.
It means that, they don't need real asset to pay the bounty hunter or in other words it's free. If they want to hire or pay influencers, they need real asset to give to them, as far as i know, top influencer won't accept new token that's going to be produced.
This is why there is intention to eliminate bounties or campaigns that only pay through altcoins or tokens. Because, there is an assumption that if companies have to pay something in bitcoin to run their promotions (campaigns, bounties), there are less scam projects in the forum. However, it is still an assumption, and no one can demonstrate it.