Microsoft was not remotely interested in a color-accurate workflow at that time, and I have no idea where they stand on this issue today.
That was then and this is now. It might be argued that the lack of Colorsync on Windows is a good thing. Win CM doesn't get in the way like CS does on Mac.
I actually saw Colorsync running on a Windows box at Apple mid 1990's–just after Steve came back to Apple. Steve "Steve'ed" it and it never shipped. Steve thought Colorsync was a critical Mac only tech. But as time has gone by, Win OS's since Vista really have no color management issues other than the obscure places where x32 and x64 keep the darn profiles...
No, there's no platform advantage to color management on Macs now and as we saw, Snow Leopard was a Colorsync disaster...
No, really, at this point the biggest drawback to Windows is really hardware standardization...there's just so many different potential components out there that configuring a Win box is daunting...compared to the relative ease of the Mac. Oh, yeah, the other thing that drives me nutz are the keyboard shortcuts for Window; ok, option is alt, command is control so what the heck is control from Mac to Win? Other than the rather drab environment of Win 7, that's my biggest problem switching between OS X and Win 7.