There a thing makes the bounty hunter gets a lot of money. Since the project become successful and raised a lot of money. remember there are some project that has putted a lot of money to be the bounty for advertising its project.
I remember someone from amber coin reach over $33k from bounty and populous.
The thing that makes bounty hunters get a lot of money is having dozens or hundreds of accounts and spaming useless posts.
I wouldn't mind all the multi accounts if people would actually write something constructive but it seems the campaign managers don't crack down much on post content and only look at basic metrics like subforum posted in, number of posts per day or number of posts within a timeframe.