Your post has made me think - always a good thing! I too almost always make the LR adjustments you describe. But, why? Is it because I (or we) are tuned into a certain way that a "good" photo should look?
- Full range from black to white.
- Few if any pure (no detail) blacks or whites.
- Some detail in almost all of the highlights and shadows.
- "Crispness" in the mid-tones ( i.e., clarity).
- And, not mentioned in your list, an obsession with sharpness.
These elements are not bad, of course, but they can be limiting if one thinks that every photo must have them. Here, for example, is a favorite photo of mine that has none of the above-listed attributes:
http://www.peteraitken.com/Miscellany/content/DSC01895_Edit_Edit_large.htmlPretty good photo, I think.