I was looking at the copy editor badge:
According to the badge page, only 275 people have earned this badge to date. That sounds rather low for the group of people who edited 500 posts?
I don't know what the requirements are for a post being counted towards this badge? I found this query here on meta. I don't know what the validity of that one is, but it doesn't seem to change at all for me?
Is there an additional requirement for a post to be considered an edit?
500
is a lot of edits. It means that you actually care about the quality of the site and are willing to do things you won't earn any rep for...