The aim of this paper is to attempt to understand why the popular academic and policy field of promoting, studying and evangelising “entrepreneurship” should have been associated with great success but, in the past twenty years or more in many advanced economies, so much failure. From the US to lesser and developing countries, emerging economies and the European Union, entrepreneurship, especially in regard to start-ups and particularly high-tech start-ups have been in constant more or less recent decline. This is seldom registered in the mainstream literature where a positive and benign profile is generally presented. The paper examines this phenomenon, ties it partly with the “productivity paradox” and seeks tentative hypotheses in relation to the apparent illusions if not delusions regarding “entrepreneurship”.