I think where it matters to me is when you are saying something is "authentic". Lets say someone is taking pictures of a beach for a resort advertisement. One could photoshop the sand to appear as some sort of rare pink color, but when you arrive that color will be nowhere to be found. Same thing if a news article has "beaches are more polluted than ever" and tint the beach to look green. That to me is akin to false advertisement.
I also agree people like and want photoshopped images since almost all photos benefit from a little tweek to saturation and brightness.
Just my 2 cents because I agree with all you said.
Sidenote if someone says "wildlife photography" and its not in the wild, its not wildlife photography.