[X-Istence]

And those ACL's are available within OS X as well, as well as within Linux, Solaris, FreeBSD (UFS2 and ZFS).

This complaint doesn't hold water. Those features are available within standard Unix environments (Solaris probably counts the most as a real Unix, OS X is technically certified Unix as well!).

So Unix file permissions can use ACL's. The default is POSIX file permissions but they aren't the only ones available.

[Goladus]

It's not a complaint, it's just the way it is. The windows (NTFS and later) default security model uses ACLs. Unix doesn't. This gives windows a few minor advantages. Yes, of course you can do ACLs on Unix. If you really need them there are plenty of ways to do it. But the limitation I described is, nevertheless, a limitation of the default unix permissions model.

It's mostly pointless to debate whether one is "better" than the other. There are advantages and disadvantages to both approaches, and it's trivial to screw up permissions either way.

The biggest advantage of unix permissions is the culture and history surrounding them, as well as the design and conventional use of the system itself. On unix, application developers, maintainers and administrators have a pretty good idea about how permissions should be set. Generally, the need to run as root is fairly well quarantined to system administration tasks. It's not perfect, but it's much better than what I remember of windows, and a quick search suggests the situation hasn't much improved. Here's a user who discovered a problem using visual studio, he was able to solve it by running as Administrator:

https://crmbusiness.wordpress.com/2011/05/12/gotcha-visual-s...

If a unix OS were to abandon too much of the conventional unix way of setting permissions (regardless of whether ACLs are used or not), you could begin introducing similar problems.