Every single one of those pieces of information is included in the original commit messages, which are included by incorporation. The merge commit message is t

Every single one of those pieces of information is included in the original commit messages, which are included by incorporation. The merge commit message is the equivalent of forwarding an email to someone and adding your comment at the top: "Really interesting, read this!" "Hey, look what Joe said..." Or the ever-popular message in CEO-speak: "?" Rephrasing the committer's message in the merge commit would be redundant at best, and confusing at worst.