Well, not that I don't want the forum to be clean from scammers, spammers, and all other sorts of users with shady behavior, but that or any other restrictions that would completely remove earning opportunities from the forum will only result in the activity dropping drastically and I don't think we want to see that happen. I believe the systems in place are pretty much successful in keeping as much uselessness out of the forum as possible, I know the results are not 100%, but it works, pretty much.

I also think that campaign managers are doing a pretty good job because they only recruit users that are capable of making quality posts and those who have joined the forum only intending to earn money from signature campaigns are barely able to get a spot in a paid signature campaign, and those who are at least actively contributing in some way in the forum are getting rewarded for their efforts and they deserve it, in my opinion. 

P.S.: Sorry for the off-topic post, OP. I could write something about the question asked but it has already been answered multiple times.