Well Mad Ice uses the D-Pad,and I'm pretty sure Asayyeah does as well.
I think it's a combination of reasons,the dual analog didn't come out until after 2097 had been released,so most of us had gotten used to the D-Pad or were using a NeGcon controller.

Multibodydynamics worded it perfectly on why I don't use the analog stick,that would probably be the same reason others choose the D-Pad.

If they had a controller that had the analog repositioned and shaped like the D-Pad that would be the best of both worlds.