I mostly get mad not because obesity isn't a problem, but because BMI is a bad way to measure it. It may work in the general, but it can give bad information in specific cases.

I'm a good example of how it fails. I have long arms and legs which causes my BMI to be fairly low. However, my body fat is fairly high. I need to lose fat but were I to rely solely on BMI I'd think I'm fine.

What I'd want instead of BMI is body fat percentage. I think that gives a much better measure of health problems.