Like most animals human beings don't want to be around other sick animals.
Chimpanzee will avoid other chimps like they have the plague, if they see any external sign of disfunction. The reasons why this happens are rather unclear, some scientists believe that it is in order to avoid the transmission of pathogens.
In any way sick organisms are disfunctional, being around other disfunctional people is a laiebility, because it is going to negatively influence your life. So we are genetically programmed to avoid sick individuals.
As human lifestyle has been getting worse and worse from a health promoting perspective, and with it the amount of disease the average individual experiences dramatically increased.
Unfortunately instead of understanding the cause of the disease and eliminating the cause and the disease with it. What most people did and still do, is to camouflage their diseases trough some sort of fashion trend.
Behind every fashion trend there is illness, like the reason why parfume was invented. To camouflage the bad body odor humans started to have during the industrial revolution, when animal products and process foods becomed very cheap and available to the majority.
They replaced they're traditional diet based on starch and vegetables, only eating animal products infricuently at large intervals of time in between, with one abundant in animal foods and chemicals, which made everyone stinky and still does to this day.
There are even fashion trends to camouflage the typical body deformities that characterizes modern humans. Like shirts, they were originally worned by farmers.
The purpose of the raised folded collar was to offer protection from the sun in order to prevent the back of the neck to get burned.
Ironically shirts are now mostly worned by people who spend the majority of they're time under florescent lights. The reason why is because the raised collar creates the illusion that your neck continues straight up, rather than abruptly bends forward. It is hunchback camouflage.
I could probably continue like this untill tomorrow, making the connection between a specific fashion trend and the disease behind it. Fashion is for sick people, if you are healthy there is no need for such a thing.
Really most people are gross because they don't take care of their health, if you would see them without any fashion tricks you would probably be repulsed by it.
The majority of disease is caused by lifestyle, genetics play only a minor role.
Almost everyone is sick, I don't know anyone who is healthy. Everyone I know has visible signs and symptoms of disease, regardless that is do to the toxicity of their diet, or they have a deformed body, do to they're sedimentary lifestyle. 99.9% of people are sick.