There are also metabolic difference for people in the different blood type group, such as diabetic, candida sufferers, LBS problems. Also, our needs change as we age. Some people are athletic, some have food intolerance. I just don't think a diet based upon a general subset of audience is worth considering.
Here is the site that delves in to the book "Eat Right for Your Type" and the doctor who started this mess. They have a sample guide for each individualized blood type. https://www.dadamo.com/