My experience in following the bounty and the reasons for quitting from bounty.
1. For number 2, it is certain that fraud will continue as long as the ICO is still running.
2. The most disillusioning bounties are successful projects, but the manager and team change the rules and cut down the allocation of funds, sometimes there are those who don't want to pay.
3. Delayed distribution by increasing distribution time.
Maybe that's my opinion according to my experience, there is a sense of pleasure and disappointment.
But for 2018 produces a lot of disappointment.