I wonder if these color schemes are chosen primarily because it's what's traditional and expected; we don't like to surprise our users/customers as it may induce negative feelings, including a lack of trust. For example, we expect a fashion website to look different to a web app, and when something is discordant with our preconceived notions we trust it less. I think that typically designers intuitively go for a less-surprising aesthetic rather than an atypical one whose aesthetic induces a degree of trust-eroding cognitive dissonance.
The one utilitarian site I can think of that breaks the author's pattern is Wufoo; bold colors, utilitarian purpose. They seem to be quite successful too. Having said that, a single counterexample doesn't diminish the validity of the author's central thesis, but it might just be one notch in the larger key.
I don't disagree that designers choose a less threatening aesthetics that incorporates familiarity. Pandering to the lowest common denominator eventually leads to the most familiar of features - GOOG is just a box and two buttons, for example.
I would also argue that the Formerly-Known-As-MetroUI pattern is also rather utilitarian. It was designed to have a low information density, but highly relevant information - that is to say, show less, but show higher quality information.
Too bad people have constantly misused those great ideas in patterns tho
The one utilitarian site I can think of that breaks the author's pattern is Wufoo; bold colors, utilitarian purpose. They seem to be quite successful too. Having said that, a single counterexample doesn't diminish the validity of the author's central thesis, but it might just be one notch in the larger key.