The Goldilocks Theory of Clothing Sizes

Yesterday I heard a physicist on NPR mention The Goldilocks Theory of Life on Earth.  He gave the example that Venus was too warm to support Carbon based life forms, Mars was too cold and Earth was just right.

Naturally, my thoughts shifted to my recent purchase of underwear from Gap.  From the drastically reduced selection of bikini briefs, I inferred that Gap seems to think that most women actually prefer either high-cut undies that skim your belly button or micro panties that reveal the very parts they are intended to cover when you sit down in your chair.  Where are the options in between?

Then I started thinking about how the Gap is not the sole party guilty of such polarized designs.  I often find myself wishing for a size between x and x+1 or an option with the width of the medium and the sleeve length of the large (my arms are abnormally long).

I've heard that clothing sizes are often based on Normal curves of anatomical measurements, which means there are only 3 possibilities:

1. Designers blatantly ignore these guidelines in favor of "feel good" sizes (HA!)
2. No one is aware that such guidelines exist or
3. The Normal curve needs to be updated.

Mostly I just wish Gap would produce a larger variety of colors and patterns of their "middle" version of underpants.