I recently encountered the Unity Reference-Only License.
Is there any freedom allowed by this license that wouldn't be allowed already simply by an "All Rights Reserved" copyrighted publication of the source code? In other words, is there anything they are granting beyond what is granted by the default copyright, as described on OpenSource.SE?
I'm wondering why they bothered to write an explicit license when it seems on the surface of it that the same effect could have been achieved without doing so. Perhaps there is some subtlety I'm missing.