Going back a few posts...

Discussing GC and realism together is just confusing two different subjects. Explicit use of GC is not a necessary ingredient of realistic renders, nor is realism a guaranteed result of using GC. 

We have clear evidence in this thread that we can get an ugly render (with aeilkema's so-called GC 'side effects') by adding GC to a scene where the materials and lighting are already giving reasonable results without GC. 

That's pretty obvious, isn't it? But don't make the mistake of blaming GC. The problem is that the material shaders and/or the lighting don't obey real-world physics. In this case, there is a clear choice open to everyone - either don't use GC with these materials and lighting, or use GC with correctly-modeled materials and lighting.

ghonma's post hits the nail right on the head - if your render looks correct on your screen, it needs no explicit GC. But using GC does simplify the process of attempting to represent real-world objects and materials in real-world lighting conditions, by giving us two things:-

1. Material shaders operating in linear colour space, like the real world;
2. Final renders adjusted for (approx) sRGB colour space, like your computer display.

GC is not 'compensation' for anything. It is just accurate modeling of the real world.

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)