This book is recommended in 『星野リゾートの教科書』(The textbooks of HOSHINO Resort). So I read this.
The myth of excellence means "the false belief that a company ought to try to be good at everything it does"(p.xviii).
The authors divides a company's features into five attributes, that is, price,service,access,product, and experience.
"different things have different meanings to different people at different times"(p.226)
In order to meet the customers' different needs companies shouldn't try to excel at every five attributes. If they do, they will look vague to their customers. They will fail differentiation.
This course of thinking looks like Jung's psychology, I think. KAWAI Hayao, who is a very famous psychologist in Japan, said that what differentiates people from others is lacks, not good features.