Plus I'm pretty sure nothing works as intended anymore. Bounty managers don't even care if their participants have red trust, and that ought to tell you something about how the system is viewed by the average user who doesn't give a flying fuck about bitcointalk.
The real question is: why does Bitcointalk give a flying fuck about bounty spammers?
It's allowed to spam millions of links to spam on social media.
And as long as they don't pay with real value, but only in tokens they made up by themselves, spamming has no real cost and only benefits to them.