XP has 'inherent visual styles capacity' too, you know....
Again, your 'point' was erroneous.
If you shutdown the themeing service in XP you'll end up with 'classic' or in other words the Windows 98 'look'. That 'default' XP appearance [Luna] is actual skinning, and quite a bit more than a wallpaper or a colour, but, as mentioned elsewhere, its capabilities are still somewhat less than what Windowblinds can do, hence the latter's popularity...