Wrong, wrong, wrong. Nobody thought that Apple, Google or Microsoft would be game-changers when they were in the startup stage. When Apple and Microsoft were in the startup stage, their customers were hobbyists. When Google was in its startup stage, it was clear to everybody that they would never be anything more than a modest compliment to what Yahoo offered.
If every startups were to listen to this author, nothing would ever get done. We'd spend our lives trying to "change the world" without making the millions of incremental improvements that are necessary for the world-changing stuff to happen.