Why are taildraggers considered more rugged than tricycle?
To expand/clarify upon the other answer, bush planes and the like use tail wheels because imagine if when landing on a rough runway, your little tiny nose wheel hit a rock.  That could be catastrophic.  However, on a taildragger, the big main landing gear can go over some obstacles, and the little wheel on the back won't pose a big problem with small rocks and such.  The little wheel will just bump over the obstacle, instead of possibly skidding on it and throwing the whole plane off.  Effectively, the plane is dragging the tail wheel over the obstacle vs. pushing the tail wheel into the obstacle.  So, that's why I think that tail draggers are preferred for a rough surface.

Feel free to correct me if I'm wrong... I've never really flown a plane in my life.  I'm just an enthusiast.