Why so bald (blurred texture) at far hills, but other large environment game doesn't

[freemangl 1]

Why Arma3 so bald (blurred texture) at far hills, but other large environment game doesn't.

eg:

Just cause 2:

http://img.6niu.com/allimg/1206/2-12061P91616151.jpg (286 kB)

http://www.gamingenthusiast.net/wp-content/uploads/2012/08/Just-Cause-2-Screenshot-2.jpg (770 kB)

outerra:

http://www.outerra.com/wallpapers/outerra_003.jpg (720 kB)