Post History

There is a difference between a flag ("this requires action that only a moderator can take") and a downvote, which expresses an opinion about the post that the community can decide how to respond to.

There may be several reasons for and against having downvotes. This answer just expresses one reason for.

## Downvotes drive discussion
### Prompting comments
I often see posts with one or more downvotes and no comments to explain why. My response is generally to add a comment. That may be a comment to express that I see no reason for the downvotes, or it may be a comment to explain anything about the post that I think could be improved.

In both cases there is now information expressed on the post that I would have been unlikely to have expressed if there were no downvotes. The people who downvoted added no content, but they prompted discussion which does add content.

### Hiding downvoters
The anonymity of downvotes makes it easy to add one without having to think or justify it. This means that a person who notices that a post is problematic can indicate this with no need to put aside time and effort for explaining. Without this anonymity, some downvotes would not be cast, resulting in less information being added to the site.

### Making downvotes count
I would encourage everyone to add comments to downvoted posts to explain what can be improved, *even when that seems obvious*. What is obvious differs widely between different people.

This is not a request for downvoters to add comments. I highly value the ability of downvoters to do so anonymously without leaving a comment. This is a request for other members of the community to add comments wherever they see downvotes.

I see this as teamwork. One person highlights that a post needs improvement, and another person responds by explaining what can be improved. Splitting this job between more people means that posts that might otherwise get ignored instead get improved.