From Google to Facebook, all the companies that I've ever researched seems to be based on people fiddling with ideas and then quickly iterate to the direction when they start getting traction.
Sure, there are crowdfunding sites or established companies selling based on CGI drawings or concept videos but this seems to be not the rule but the exception for the products that I use. What seems to be the rule is that people have some ideas, they build MVPs and fast-iterate or pivot based on the reception.
For the b2c, at least... Anyway, the article is probably talking about b2b where it can be O.K. to start with some slides of value propositions and build the thing later because of the selling process taking moths and the implementation, potentially years.
edit: hmm, maybe I am taking the "selling" a bit too literally.