That's why they have a section outlining some of the Index score's limitations. It's not like they're hiding this stuff. I will grant that the iPhone app describes the BMI as being "a reliable indicator of total body fat" which it is not, as explained on that limitations page. Still not seeing a conspiracy, I'm afraid.
At the age of five, Skagra decided emphatically that God did not exist. This revelation tends to make most people in the universe who have it react in one of two ways - with relief or with despair. Only Skagra responded to it by thinking, 'Wait a second. That means there's a situation vacant.'