You're leaving out the alternative, which is the important part.
If you pull rebase, then that merge commit will be whatever the author of the commit decides it should be.
If they currently have ten files open, the merge commit will be ten files, regardless of how connected these files are, which is a lot of noise. With a pull-rebase, when they are ready to commit, they will decide to break it down nicely in 2+3+3+2 files.
The only person who should decide how to merge their files should be the person that modified these files, not git.
If you pull rebase, then that merge commit will be whatever the author of the commit decides it should be.
If they currently have ten files open, the merge commit will be ten files, regardless of how connected these files are, which is a lot of noise. With a pull-rebase, when they are ready to commit, they will decide to break it down nicely in 2+3+3+2 files.
The only person who should decide how to merge their files should be the person that modified these files, not git.