Microsoft has a history of playing fast and loose with standards, suffering from NIH syndrome, and lack of cooperation with (or outright hostility to) Open Source projects that want to inter-operate with them. Since they're the de facto standard desktop OS, the rest of the world's just gotta suck it up and deal with it.
Hey, it could be worse... try getting your Linux server to play nice with an Active Directory domain (i.e. use the Windows DC for Samba authentication) sometime!
(We managed to get this going a while back, with Debian Linux and Windows Server 2003... getting it to work again
with a newer version of Debian and Windows Server 2008 is the last thing holding up the cutover of a new Linux server for the Software Engineering group!)