I would like to see this done well. However, with Apple trying to protect and cater to the "every-day user", I wonder if we will ever see something like this, because of the security implications that come with it.
They do need a filesystem and interoperable components. What they do NOT need is a hierarchical based filesystem that limits you to a directory trees. It's an organizational nightmare, and unless you've ever used git before it's a literal hell for the average user.
Instead, a flat filesystem with smart names, tagging, and metadata is the way forward. Subdirectories will be relegated to those who want them.
As for security, that excuse is nonexistent when Apple has the final authority to application interoperability and analysis. If an implementation is flawed, they can reject it at will and tell the developers to improve it.