While you may be correct, those are basic functions that do not compare to what NT has. On Linux, you have to mount the FS with ACL support (I don't know if this is the default now) and manage them in parallel to the file system permissions, complicating the security model (without even going into SELinux and SUID 0 stuff). Due to legacy reasons, Linux's security model has evolved, while NT has had the luxury of a do-over during its design phase.