It's not just micro-triangles, it works for triangles that span multiple pixels. And that's not a special case, that's the standard nowadays, except for games targeting very low-end devices.
The dedicated hardware is nice for general-purpose support for arbitrary triangle-soups. But if you structure triangles a certain way and have a certain amount of density (which you want for modern games), you can specifically optimize for that and beat the general-purpose hardware rasterizer.
