[billmalarky]

>While it is true that BMI is not always accurate as a measure of fitness

You're right. I've never seen a fit person complain about the inaccuracy of BMI in anything other than a joking manner. It isn't precise, but it's "good enough" for the majority of people. It's a heuristic.

On the other hand, people who are clearly in poor shape love to scream up and down about how inaccurate BMI is at determining fitness levels. Ironic because BMI generally puts non-active people in a positive light. If we switched to body-fat percentage something tells me a lot of these folks would be clamoring to get BMI back since it under-reports people who have low enough mass to be not considered obese, but too high body fat to be healthy (thus are at greater risk for diabetes etc).