Honestly signature campaign managers shoulder a lot of responsibility in the forum, some users might not notice it but they do, quite a lot of users are on a signature campaign, and many of these managers make it a criteria for the user to be a decent poster, i am pretty sure this has encouraged a lot of users to work on themselves and bolster their knowledge, so on one hand they get to learn a lot about Bitcoin, post quality stuff and then earn some 'pocket money' via signature campaigns; so campaign managers have a lot to play in the quality of posts on the forum.
I do not always completely agree that signature campaigns are a source of evil, spam and incompetence on the forum. Yes, it is impossible not to notice that many users stay on the forum just for the sake of this income. But I, as a user of not very high rank yet, think that this is more typical of high rank members who before the merits of the system have received a high level and can now use it without improvement. For example, this is my first experience in the signature campaign, and when I got acquainted with the criteria, I realized that one can't get there just like that, one has to meet quite high standards. Therefore, my acceptance was a very high assessment for me, on a par with every earned merit. I think this question depends on how you feel about your work and how honestly you can evaluate your efforts. And I'm grateful to the campaign managers who set the conditions for members to improve.