I think the most reason why people run away from the bounty is that they don't get any update from the bounty and they see that many of bounty is a scam and don't pay the rewards to the participants. In 2018, we see that almost all bounty campaigns delay their payment distribution to the participants because the dev worried that their token doesn't have a good price in the market, so they decide to delay or cancel the project and to wait for the market to rise again.