Because bounty managers are not moderated, only tag from DT members is not enough,...
Let try to get a red trust with comment "Cheating bounty with alts account" and you will know what effect of work that DTs are doing.
so when theymos still doesn't want to control this, it still happens.
Actually, this name of forum is Bitcointalk, not Bountytalk. Even Altcoin section just appeared in few years ago. And Bounties is a child board of Altcoin section, it is as a sub-part of Bitcointalk forum. If theymos and his team decide to excute Bounties section, Bitcointalk will be still alive.