[yoklov]

Should as in "it would be nice"? Maybe.

Should as in it does already and this sort of thing is unnecessary? Definitely not. Hence EXT_sRGB.

[nightcracker]

Should as in "I believe WebGL + GLSL already does this by default, it does at least on my machine".

[yoklov]

This would be in violation of the standard (in a way that would cause a lot of things to render wrong -- anybody who was rendering correctly would now be wrong!), and also it isn't practical in most cases.

It's a common misconception that this is taken care of for you by <platform X>, but it basically never is. I'm positive this is the case for WebGL.