And herein lies the problem. If you aren't built like Barbie or Ken, you are obese by these loose standards. Precisely right. BMI does not take muscle mass into account; as a result, as you illustrate, some of the world's greatest athletes can be considered "obese" by this silly standard.
Just for fun, I computed BMIs for the entire Pittsburgh Steeler's active roster. Among the 53 players, this was the result:
33 players (62%) were rated obese.
19 players (36%) were rated overweight.
1 player (2%) were rated normal.
Who was the normal BMI player? Nate Washington, a respectable starter but by no means one of the pillars of the team.