The article’s premise intrigued me but it was a disappointing read. Gourvennec just presents the typical and tired argument that user-friendliness is subjective and personal [really?], so you can’t really measure it [no?], and therefore you can’t study its impact on sales and revenues.
Anyway, he says, there are many examples of difficult to use products which have become big commercial successes.
For a site that deals with “visionary marketing”, some more vision would be helpful.