To some extent exposure in landscape shots is as subjective as composition. Try setting the mode to Manual and centre-point only exposure reading then waft the centre point around the subject area (as you may wish to do to choose the most important focus point to lock onto), you will find a considerable variation of over/under exposure read-out. In manual mode, YOU then make the choice of the appropriate exposure.

If you set the mode to a camera programme such as landscape, the camera decides for you.

The beauty of shooting RAW/NEF is that you have a 2nd go when postprocessing using the basic data collected by the sensor. This is different and less likely to lead to noise and un-natural colours than if you 'comb' out pixels using levels or shadows/highlights in PS. That is because the camera sensor collects the info for both over- and under-exposure cases. NX is a higher precision tool set for then teasing out what you want than is PS.