BMI has it's weakness with muscular individual being labeled obese. . . But it's not the muscular people who complain. As a physician, the only people I hear complain about BMI being inaccurate is those with lots of fat tissue. . . Occasionally a OLine type person with lots of fat and muscle.
Plain and simple, being fat is unhealthy. Being unhealthy is unattractive. While different people's opinions will vary about how much healthy plays a role in attractiveness. . . Being healthy will always make life better.
I just played soccer with the Young Men last night, having recently fought to get back in shape for half the Summer. . . It felt great to run around with the teenagers. I couldn't do that effectively back in July.