Actually, the problem is bounty managers are looking for mass workers, not quality workers. If only quality work is accepted I can bet 80% of participants will leave this work after a few campaigns. Also recently some low-rank bounty manager appears who doesn't care about their reputation and ready to promote scam project if they got money for them. I also think we should leave that matters for now.
The usual bounty campaigns are just numbers in social media. Shill in Twitter, Facebook, Reddit, Medium, and may other platforms. There are no genuine conversation but all misinformation. The bounty hunters even do not understand the project. Project team, campaign manage know it but they do not mind, they are not paying anything for it at all.
It's the market that turned wrong. It was a lot better in late 2017 at ICO peak time. Because these tokens had at least some value back then. A user who is a little informed they know it's waste of time now. Only the new people who heard that they can make money from bounty, they try. After few participation probably they realize the reality or why do we see many newbie fresh accounts in bounty campaigns.
The bright side is, from these newbies sometimes we get some people who find the forum interesting and continue. We have so many such examples.