I think, before joining a bounty, you have to research bounty manager well. You should read the texts in bitcointalk about the bounty manager. And especially if you sign up for a signature campaign, you should also research good the project.
I think this is not about the bounty manager though having a good reputation manager is a plus. What happened with the project that the op joined is clearly because of the project itself, maybe the project was not good enough for the investors to get in or also maybe the bear market effect.