I think the author makes the wrong assumption that his product does improve health and that the current practices of GPs or other health professionals don't (as much as they could). He misses the most important thing of any professional and successful health care worker: experience.
If a doctor has a high success rate with drug A on their patients then even if some website tells them that drug B _could_ be slightly better why would they try it? There has to be more of an incentive than _just a website saying so_. The doctor has a high success rate with drug A, has seen it working many times and knows everything about side effects or maybe the lack of those. If nobody has complained and it works miracles then it would be foolish for the doctor to start prescribing a new drug simply based on a random website's recommendation. Also doctors do have to stay current and they get medical journals sent home, attend training courses and conferences and learn about new stuff when it's actually relevant and needed.