it's normal if projects discontinue and refunds to investor, then projects will not pay bounty rewards because it's just a useless tokens, even if project reached their softcap or hardcap target, still have chance don't pay for bounty participants, try to use the forum search functions, a lot of similar scam cases, example: envion and tokenpay
Yeah, that is one part of the risk of being a part of a bounty campaign and that is why sometimes it can be quite rewarding as well. Most of the team understands the risk you are taking in promoting the campaign and the possibility of you knowing that you getting paid are dependent on the success of the ICO, which is why you can simply get something substantial over time, depending on the campaign though.
Most project that would reach their soft cap or hard cap and end up not paying bounty hunters actually show a fraudulent team in that aspect, which is why it is necessary to always look out for the team, the availability of product before even deciding to invest.