The irony of BMI is that people with plenty of muscle mass are more likely to have a high BMI as well as lowered risk for heart disease.

BMI was never meant to be used as a diagnostic measure. BMI is just a rough filter for large data sets, and entirely dependent on the average height and habits of that population.

Anyone taller than about 6'3" could tell you the recommended weight according to their BMI has always been absurdly low. If it's a printed chart on the wall, they might not even be on it.

BMI is not a good metric for really short and really tall people.

The "ideal weight" of a person is proportional to height to an exponent somewhere between 2 and 3. Simple physics would say 3 but because tall people are not just scaled up copies of small people, it is closer to 2 in practice, maybe around 2.3, but we say 2 because it is easier to calculate.

The downside is that BMI overestimates the "ideal weight" for short people and underestimate it for tall people. But BMI is not great at capturing exceptions anyways, so there is little interest in "fixing" this.

This is a common misconception. BMI while an ok population metric, for individual's the biggest problem with is its poor sensitivity - it fails to classify people as obese who are obese.

Using your 6 3" male as an example, they are significantly more likely to be clinically obese (using waist circumference, body fat % etc) at a weight lower than BMI cut-off of 240 lbs.

Americans that are 6'3" (190.5cm) are about 1.5% of the population. It is a tiny fraction of the population.