Why is there a "Neutral" Curve?

I look at the actual inks, and I see 3 shades of warm, 3 of cool, and one ultra black. So shouldn’t there just be two curves? Isn’t the Neutral just a blend between cool and warm?

I guess if I want to print 100% neutral, then maybe, but I could also just choose 50/50 between two curves.

I am particularly curious, since that curve seems like extra work that is otherwise unnecessary. Such as profiling yet another curve, selecting it in the curve selector etc…

The neutral is not a 50%/50% split between the warm and cool…it varies depending on the paper, between 18-25% warm (see an explanation in the deluxe manual on page 86 under the blender tool). I for one prefer to use a neutral curve at times because it’s far simpler than trying to do the calculations in my head when I want to make a split tone like a warm-neutral. I go to the trouble of creating that 3rd curve for some of my papers.

-Mike