I know this is an old thread, and I am far from an expert on scale color, but it is a topic that interests me greatly.
I am very much in favor of it, and here's why: you can scale down a model, but you don't scale down the atmosphere with it. Scale color is just atmospheric perspective (also called aerial perspective). Air's not invisible. The more air between you and something, the more air you can see. Things at the horizon tend to be muted out toward a bluish medium grey.
In simplest terms, there's a lot less air between you and a small-scale model than there would be between you and the real thing at a viewing distance that would approximate the experience. I've seen photos of small models, such as a 1/72 80' Elco 80' PT boat painted in the experimental adaptor scheme (zebra stripes). The black was too black and to my eye in spite of the model being extremely well crafted it looked like a toy. Black, in particular, needs it. It will hardly be noticeable on grey things. A lot of subs are black, though (including my planned Gato) so muting that black out a bit will pay big dividends on the shelf, and some dividends on the lake.
I left engineering school unceremoniously, but i did manage to survive art school. Atmospheric perspective is very effective in giving the impression of space, but I don't think you can tie it to a calculation. Weather conditions, especially humidity, affect how much air you see. There are just too many variables, but I think a somewhat understated version of atmospheric perspective can pay big dividends.