I guess that such things happens, probably not every person who runs campaigns is fair. But I doubt that happens at big scale. I just have nobreasons to suspect one or another member. Maybe it's not good thing, but I tend to have good initial opinion about people.
If I could say on this view or point, I think it is because most of those accounts are having negative tags and would find it difficult to be accepted in other campaigns if not campaign run by 1xbit or affiliates. I think that is the most plausible reason that they suddenly wake up to apply there. Meaning that

, they are also alts of some users here and maybe reputable members too

Yeah, I also think so. These accounts with red tags is basically worthless and only way to monetize it is campaigns like 1xbit. But I guess that some of these members have alt accounts which are clean and enrolled in other campaigns. They stay active on forum and this is how they notice that 1xbit campaign is available.