A person's physical condition presents many indicators of their attitude, character, and mental state.
A person who is not willing to make an effort to stay in at least moderate physical shape, and is not willing to make an effort to be at least moderately well groomed, is not going to be willing to make an effort to keep you happy.
Agree with your points. There’s an old assumption that people who are fat are indeed lazy in general and thus far, it seems to be true...