Correct me if I'm wrong, but isn't the problem that Linus brought up this: If you introduce a new object type, you need to get it right. A new object type would create non-backwards-compatible repositories, so you'd have a new minimum Git version. If you were to use this fork, then everyone who checks out your code would have to use it. Also, it would preclude tooling support (eg GitHub). Once such important repository versioning decisions are made, they can't be unmade. Git, at it's core, is basically just a well designed repository model.
