that supports his point...?
Terrain isn't bad but doesn't have any sloping at the bottom so it looks bad. Its a bit late to fix, though, since you didn't build on a baseplate.
Keep in mind next time you start cliffs/mountains to not start directly on a flat baseplate or ground; shaping flat terrain is just as important as the mountain terrain.
Read up my
guide if you haven't already, it explains what I'm talking about here better, with pictures. Flat terrain, under the Normal Brickscaping section.