I can understand where they're coming from but, for the life of me, I can't recall the last time I needed to restore such code after a long gap. If the code's that interesting, they can either leave it on a feature branch or refactor it out into a reusable module or the like.
Second that, usually I see worthless snippets commented out. Those are good as reference for a couple of hours when you work on the code but when you are done the commented code is lie and new code is truth. Also I cannot imagine working on a piece of code without looking at git history to get context (commit messages linked issues in tracker) in this way commented code from past has no value for me at all.
