We don’t simply get to pick and choose characteristics that we’d like to get rid of. You cannot just make-up genes that will prevent balding, acne or obesity. If natural selection were to take it course, people who have the aforementioned characteristics would be less likely to breed, and therefore, they wouldn’t pass on their genes. However, bald people (usually before they become bald), obese people and people with acne still breed. And acne and obesity isn’t necessarily something that’s hereditary. They both have to do with your diet and washing habits, along with horomones.

Baldness might not emerge until after the person has reproduced.

Acne might exist before the person has reproduced.

Obesity can have a genetic predisposition involved, but is usually a result of choices, and not solely genetics. Keep in mind the recent studies, too, that suggest that you are more likely to be overweight if your friends are too. (The same goes for mates.)

Plus, not everyone is a perfect "10," right? Usually 10′s pair with 10′s, and 1′s with 1′s, right? Not to be harsh or anything…

And don’t forget the effect of beer goggles….

Besides, some of the unattractive traits that might turn you off might mean very little to someone else, who sees beyond those things.

Obesity, at least, may have a selective advantage. It represents fat stored against time of famine. You might note that our definition of beauty changes with the economic conditions. When times are tough, plumper people are considered better-looking. The reverse is true when we are in a boom period. It’s not a matter of a directional pressure so much as changing fads. Skirt lengths are also affected by economic conditions, BTW.

Baldness and acne are closely related to hormone production and might actually be selected FOR.