story
`.gitignore` is for stuff that all developers need to ignore, like compiler output, and should be kept to the bare minimum.
But that is the case, all developers need to ignore the ".DS_Store" files. So by your own rule it is appropriate in there then?
And, for what it's worth, all developers need to ignore .DS_Store files regardless if Finder creates it or it gets placed in when you unzip something created on a Mac, for instance.
In the best case, you spend extra time needlessly denying PRs and bothering people who already likely don't know git well enough to cleanly fix their commit. In the case of a repo large enough that you're not the only person approving PRs, I'd say it's almost inevitable that they eventually slip through.
Just my 2¢ from experience working in the industry.
