The issue is where does this information go.
If in a central place what happens if the original directory is moved - how is the metadata updated. - Unix is another file somewhere, Windows can be in the registry.
With Apple it is kept with the directory.
The issue is that a directory needs some metadata and the Unix design of everything is a file does not allow the directory to include this without adding another file somewhere.
The POSIX file system is not the perfect thing.
