Indeed!! I read the article, author makes some good points but in others - like the car paint colors, that is more down to the cost of paint colors. (the black, grays and whites are less expensive.) Might be the buyers are looking for cheapest options and the manufacturers are meeting the market. Same with the similar book covers. (though that is also design laziness and also tied to waves of designers fresh out of the schools that were taught the same tricks with Photoshop and they churn any given "look" out. Those kinds of covers the publishers just phone in..) It's demographics and economics.

Definitely though, the newer forms of deviations are happening in ways that haven't been accounted for yet.