Quote-"Oh come on, we've been through this time and again: what is superficially more pleasing to the eye is not necessarily what is correct. hawarren's comparison clearly shows the GC render as far superior in tonal balance and contrast, but because the lighting was adjusted to be correct for the non-GC render, the non-GC render may appear more pleasing to the casual viewer."

When speaking about art your statement is absolutely false.
A friend of mine who works at a production house put it this way, "We like our work gamma corrected because that way we have a neutral canvas to apply post production enhancements. If what you're going for is dramatic lighting then you don't want "tonal balance". In fact you want the opposite"
In the above pair of renders the one on the left is clearly more dramatic and therefore more interesting.

What is superficially pleasing to the eye is what art is all about.