Well, i agree with your point of view that people need to improve first and then convince to remove the negative / Neutral feedback, but in both cases, they have to send the PM to the DT member to bring this matter to their attention. So when a few genuine people (who have improved their posting habits) will PM DT, at the same time a lot of others will PM too who haven't improved.

A shit Poster can improve and can become better while a good poster can be at times becomes a shit poster. Ideally, when we give feedback to anyone about their posting quality, it should be checked after 3 months or 6 months to see if he has improved. Since people usually forget after giving feedback, so the only option left to the people is to PM the DT members. I would not call it begging because it is the only option if you have improved yourself and want to bring attention to the DT member.