Somehow, this reminds me of the horrors of secondstrade when it was still around. Similar structure, loose rules, etc.
If people accept these horrible rates, then so be it. But the problem is that only spammers will apply to this campaign because a) they have no competent campaign manager, b) the rates are low so they don't have any competition and c) they are able to get paid to do the bounty stuff that they are already doing.
As long as Nexybit pays, I don't think that you can accuse them of being "scammers". But it certainly makes the unprofessional considering they are essentially explicitly employing spammers as their promotional medium which will not end well for themselves.