Are you asking why Linux doesn't enforce the file protection modes when a NTFS partition is mounted? It does however it has to map the NT user accounts to user

Are you asking why Linux doesn't enforce the file protection modes when a NTFS partition is mounted? It does however it has to map the NT user accounts to users and for ease of use the mapping is to map all of them to a single user. When an NTFS partition is mounted as a removable disk, the protection is ignored, and all files are readable and writable in the same way that a FAT partition would be. The ownership of the files is assigned to a specific user. Normally the one that requested the mount.