Makes sense, since no one was interested in maintaining it.
But as long as they have some solution for this problem (and I think it is pretty common, because debian always installs with generic drivers for your hardware), I think it is no problem to remove the fallback mode.
You may find you just like using it....
IIRC the reasoning was that GNOME Shell is too big to fit on the default install CD, rather than any idealogical thing.
- Most of GNOME fits onto CD#1 again (network-less installation).
- LXDE and Xfce now live on separate images.Shame, XFCE would be a good default.