If we want to solve the spam problem, then we should just actually enforce the rules regarding spam and signature campaigns and start handing out temporary bans like the rules say we will.
But, shouldn't campaign managers be more rigorous in the posts they count?
I can even accept that it is not always easy to check one by one the posts that campaign participants make. But, I believe that these users who have a very low level of quality in their posts are easily detectable.