Bounty scams are unlikely to disappear in the market because as the cryptomarket grows and grows, exploitative people are also increasing to do these scam projects. So we just have to be more critical of the bounty projects we participate in, because learning is one of the good process of indentifying good ones.
One of the issues is that cryptocurrency is a relatively new market and every year we have tens of millions of people who are investing in it for the first time. The scammers mostly target these people, who sometimes fall in to outlandish claims of massive profits. To complicate things further, cryptocurrency is decentralized and there is no central authority where the users can look for guidance. And if they turn to other sources, there are more scammers then ordinary investors present.