Anyone know why? Given ext2 has had a public domain implementation for more than a decade? Is it because windows & mac won't support ext2 even for free? Seems like a better lowest common denominator fs than any of the fats?
That's because Linux and OSX ignore NTFS permissions making it work more like FAT.
Plug an existing NTFS drive from one Windows system into another Windows system and you get a similar issue where opening a home directory requires you to take ownership.