I note that negative ratings follow people around forever, even though many of those ratings were obtained at a time it was easier to do so (by just being 'disagreed' with, I think). Also, people change - perhaps they get stressed arriving in a new country and react to the perceived frustrations. After a while they settle down. I would like this site to be a positive place and perhaps after a year or two (or less) these ratings could be removed. One VERY WELL KNOWN contributor (who shall remain nameless Mr R) has 10 past and well out-of-date ones - yet his positive contribution to this site is so great that I feel he does not deserve to carry them around forever. I know many will say that ratings don't matter that much - I agree, but sometime a person arrives on the site and is so obnoxious that he soon accumulates enough to be noticed and banned. But after a short time those ratings have served their purpose.
I don't think it's a problem. Not many people have a negative rating and those who do don't seem much bent out of shape about it. Creating some sort of thing to remove them is just another item to add to the todo list. It seems to be working fine, so why mess with it? There seems to be two sorts of people who will get these ratings. There are people who make a lot of posts and get a negative due to much greater probability of making a bad post and then there are those who turn out to be bad apples right away. The people who post a lot aren't bothered. The people who stack the negatives right from the beginning don't seem to last long. It's good to keep those around as a reminder in case that account wakes up. It's probably a good reminder for those who own the accounts as well. I know I makes posts which are on the edge a lot. My little reds remind me to behave.
Disagree was never a negative rating. No idea how to make that happen. Personally, I don't mind having the negative ratings. Many of mine were given by the turds who were banned due to negative ratings when they were confronted about their turd behavior. They come so rarely that it isn't even worth the time finding the post to remove them. The ratio is all that really matters for users under 500 posts. Get too many of them and you'll get automatically banned. Since it takes some people a really long time, if ever, to get 500 posts having them removed may negate that setup. They really are only for moderation proposes. I can't possibly remember the post history of every single user and they work as a guide on what type of action should be taken.
