[thrwwycbr]

I kind of agree with this argument, too.

The process of signing a commit is used in a kind of wrong manner, I suppose, because of your mentioned points.

The "view of the file tree as you saw it" basically implies that signed commits aren't worth anything if the code is refactored or changed later, which inevitably it will.

Using tags as a reference point, however, is the idea of snapshotting a mutually agreed state between multiple parties working on the project.

I think you could take this a little further, and use it to implement a Q&A workflow, where e.g. a code review team and a testing team should sign a specific snapshot as "working as we saw it", and that could integrate very well if you e.g. have a semantic version epoche of your project.