You're only seeing the signature everywhere simply because we run the biggest campaign on the forum.. BTW this discussion isn't about stake. Let's focus on the topic.
I have 121 members in the Duelbits campaign
As for the topic at hand, if we were to police this theymos would have to get involved and babysit all the campaign managers (or hand pick them) which I don't believe will ever happen. As such, it's nice if a few managers can band together and have some sort of QA when running their campaigns but in the end the clients will either go with their first contact or whoever is cheapest (looking at you $25/week campaign managers).
One approach I have taken over the last year or two is that I do these "cleanups" where I remove a number of members in any of my campaigns in order to get fresh blood in, some people tend to get complacent and just post to get paid after some time and this hopefully keeps everyone on their toes. I do however also have a bunch of users who see it as a job where they HAVE to hit x amount of posts but I always tell them that if you are busy or you have shit going on in life just take a break and get back to it when you can do it naturally. We need to get it back to a state where it's considered a perk rather than a job but we might be too far gone there too.