> why you would object to having more metadata attached to your commits

It gets in the way because it takes pride position at the start of the commit message. If you want to put it at the end that might be less annoying but I've never seen anyone do that.

I think the main point is that I almost never arrive at a commit by exhaustively reading through a list of commit messages. It's almost always through some other kind of link like git blame or a GitHub issue/PR.

It's also just really low value information. Imagine if every commit message started with how many lines of code it changed. That would be pretty annoying right?