Bounty managers pay you for job you do for them, this is not a charity. And they can ask for any specific rules they want to feel comfortable and know they will get what they want in the end. Your choice is to participate or not.
Exactly! It is a world in which as you have people who are trying to do right, there are some who are just bound to want to do wrong by default.
Moreover, in the land where there is no rule, then there is no sin and definitely in that kind of scenario, everyone is going to be doing whatever they feel like without any single remorse about it. Considering how a lot of people have been trying to cheat the bounty system without strict rules in the past and because of their greed, it sure shows that human behaviour at times, require some control with the help of strict rules.