Ashley Bye wrote:. . . The only reason I can think of is users editing their post to remove or significantly change it after one or more replies, thus losing discussion context. . . .
Unfortunately that used to be a frequent occurrence, which caused some of us no end of annoyance. I was one of the people it annoyed more. When we had the edit button visible that sort of thing could happen every twenty‑four hours or even more. It takes very little effort for us mods to edit a post on request.