It's a nice post but I feel a distinction is necessary. When you're talking about only goods, I agree. But when discussing Service as a commodity it has be viewed as necessarily irrational, because service, etiquette etc. are matters of personal taste.

Surely there are guidelines and various basic constants (I prefer no spit in my food!) but when it comes to nuanced service the model was never intended to have a rational or consistent audience. For example massage - each person's body is different, it has different needs and therefore various types of massage are appealing to various types of people.