You've done the right thing here to try and eliminate as much of the bright white featureless sky as possible though it still had an influence on your camera's light meter causing the main subjects, rock and cactus, to be under exposed. One way to resolve this would be to take a meter reading off the rock only (either with spot metering or by filling the frame with the rock) then locking the exposure and recomposing to what you want in the frame.
It looks like the sun was bright. If you would have waited until the evening or earlier morning, the details from the rock and catus would have come out I think.
Of course, I'm no expert on lighting. I do think the light is taking away from the subjects. 4