You had a very nice idea tho I don't think any project wants to do that unless there is strong pressure from everyone, not just bounty hunters alone. Why paying a fee to conduct bounty aka escrow as long as no one can force them to do that?
Yes, creating a bounty and escrow is something that you don't have to force if the project doesn't need it, but if that is done then there will be a good effect for the project itself, because on a real foundation they will be really strong in the future. if the project can be successful in a timely manner.