People are misunderstanding what HDR (and to an extent, bloom) actually is. HDR is just a way of representing brightness levels that are beyond the capability of the medium displaying the image (hence 'High Dynamic Range' - a monitor by contrast has a Low Dynamic Range).
One of the ways this can be implemented is by using bloom on areas that are lit brighter than the backlight of the monitor can acheive - like the sun, or a car's headlights. Whether or not you like bloom in a game (and I admit it is waaaaay overused by most) you have to agree that things like headlights look much better when they have glare, rather than just 'making the texture white' as is the current LFS implementation.
This thing of having the screen dynamically brighten and darken is just a way of coping with the fact that if it didn't you'd get points where the entire screen was either bloomed or dark. I know which I'd rather have.