That is a terrible conclusion to draw. BMI is a horrible indicator of health and to say that this study has no merit to "normal" people is idiotic. Also the jab against people in the US doesn't have any place in a scientific discussion of this study. Keep your prejudices to yourself next time.
BMI is fine as an indicator of "are you fat or not", UNLESS you are a very fit athlete. However being fat and being unhealthy aren't 1 to 1, contrary to popular bias and stereotypes. I've known plenty chubby and healthy people. They might not run marathons but get on with their lives just fine. Certainly it can raise your chances of being unhealthy but it's certainly not 1:1 as many online "experts" seem to claim.