But if the project is obviously a scam or there are pieces of evidence that the project is a scam the manager must act to stop the campaign, a good manager will not hesitate to do that and is not selfish even if he is going to get paid with tradeable coin,
If you're a bounty hunter you need to set criteria on the kind of project that you're joining, don't join for the sake of joining work smart not harder, you don't have to join everything you only have to pick the right one.
Completely agree with you. Manager is also responsible, at least partial. They should do their homework about project before accepting job. Offcourse, it's not always possible to know that project may become scam, so, manager don't have full responsibilty for these things.
No, manager cannot always know whether a project will end in a scam but managers should look into whether the developers or the company they work for are as responsible as they should be. In my opinion manager should do their best to find out. For example, a manager should stop a campaign when a red flag is detected, such as plagiarism in a white paper, and ask the project owner for an explanation.
In most cases, managers just do their job. But sometimes things go so badly wrong that the manager has no choice but to close the campaign. I have seen many good managers stop bad projects where the developer has committed serious errors.