BMI is a great tool for its intended use. The problems occur when it's applied too generally, without taking adiposity, muscle and general fitness into account. People expect it to be a) completely accurate rather than a guide and b) apply to everyone.

It doesn't work for athletes, people who do lots of regular exercise, younger people or older people (except with different data sets and formulas). It does work in most cases for sedentary people who are carrying excess fat.

It is encouraging to see the people here taking a more complete look and seeing things like lean-mass as part of the picture, it leads to healthier outcomes