Thinks of it this way, since the project team can easily mints the coins in whatever amount the wish, it will cost them nothing against paying in dollars or other stable currencies.
-If the team is serious about growing their project, and at the same time paying a reasonable amount as a reward for their promotion via bounties to the hunter, their can as will pay in their token in other to protect the market and possibly dump, they could offer some form of buy back, in that way, the team will buy back bounty allocation from biunty hunters, that way it becomes a win-win for both the hunter and the project itself.
To be fair, the bounty projects themselves are not serious in their project development, their goal is also scam after a while. As far as I know, the amount of tokens for marketing only accounts for 1% of the total supply of the project, so when the hunters sell tokens will not be able to cause the project to collapse, this is absurd.
You are right, they can easily mint the coins in whatever amount they wish, they are just taking advantage of hunters to help them develop the project but don't want to spend money. Projects from bounty campaigns are mostly trash and not serious in project development, if they are really good, they have been noticed and invested by large investment funds.