This feature is still present in later versions of Windows. There are, for example, high contrast "themes" for Windows and pretty sure starting with Vista there was a standard feature of a screen reader. You can even still switch off Aero and make the same changes to menus you described (may even work without disabling Aero, never tried myself). You can also increase the scale of what you see on the screen so it's a bit larger in general.
Office, of course, has always been kind of a different story. Microsoft routinely uses Office as a means of testing new UI concepts. Office 2000 introduced flat menus which were all the rage for a time, then they went back to a kind of understated 3D, now I guess with Windows 8 flat is in again. So, whether or not Office will ever honor OS level settings for visually impaired people is basically a crapshoot. Always has been, probably always will be. Of course newer versions of Office, with the ribbon UI, don't really use menus, so could very well be much more friendly to someone with visual impairment. Instead of tiny little icons littering toolbars across the screen, and menu after menu of option, there are big large buttons and the commands that used to be in an endless array of menus are now arranged in tabs... With big large buttons. In general Microsoft has been trying to get rid of menu bars as much as possible, STARTING with your beloved XP.
So, it kind of seems like you're just looking for an excuse to complain, you just stopped when you couldn't find any specific reference to the particular feature you were looking for. You didn't take the time to discover that maybe the feature was made unnecessary because of a fundamental design change. And of course, whether it's right or wrong aside, visually impaired people make up a very tiny segment of the overall customer base for Windows. That they make any concessions at all is likely only because it's a requirement to get government contracts.
If it is that big of a deal to you, you are free to go create your own operating system designed specifically for visually impaired people. Maybe once you have some appreciation for just how much effort goes into even the tiniest of features, you'll be a little bit slower to complain.