[Brightcolours]

How much do you have read about perception and computer graphics?

Asking such side tracking questions does not help you (and I have read more about those than you, is my guess. I have been developing software since the 1990's, including specialized presentation solutions back then). Just simple fact: high dynamic range puts two values relatively close together, high contrast puts those two values far apart. Computer graphics have nothing to do with that. 

 

I doubt you ever really looked at a high dynamic range image (no, I do not mean a low dynamic range image derived from a higher dynamic range via compression and tone mapping), but anyone who has ever used high a special high dynamic range B/W film formula and low dynamic range colour slide film knows that DR and contrast are opposites. 

 

High DR puts the black and white points far apart, what we in reality perceive as black and as white will look like a grey (almost mid tones) in high DR captures (talking about perceptions...). Not sure why you confuse contrast with high DR.

 

On the left a normal tonal curve (the way our eyes perceive the world) and 8EV or less dynamic range (which is normal). On the right a dynamic range extended to about 14 stops.

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Notice how the "blacks" turned into greys, and the light parts turned into greys too. That is how a high dynamic range capture looks. Why is that? Because a high DR pushes the black- and white points apart (obviously, you are extending the dynamic range). Increasing contrast will pull them closer again.

The low DR image looks contrasty and punchy, the high DR image looks flat. Only by turning the high DR image into a low DR image one can make it contrasty and punchy again.