Ugly people have also been discriminated for years because they don't get the same job opportunities as good looking people.
They earn less, are less likely to be promoted, are less likely to get into political office, and less likely to get many opportunities in life.
People who are attractive are seen more friendly, sociable, reliable and competent than ugly people. Ugly people are seen as lazy and unproductive. Unlike race and gender, ugly people is not a protected group by law. And is even more of a factor of discrimination than gender or race because of no law protection. Ugly people have been a disadvantaged group for thousands and thousands of years. Even before modern humans walked on this planet. Our ancestors treated attractive people much better, and more likely to breed with them then ugly ones.
Not only that but theres also height, age, weight, genetic intelligence, geography, time period, health, wealth, natural athleticism, family structure, friendship (knowing someone in business), and many other factors. These affect all groups of race. White, black, hispanic, male, female. And hardly any evidence that these factors are less important either. Some of these are even more of a factor then race and gender. Why don't people attack these as much as other variables that can affect job opportunities and status? Why only focus on gender and race?
What if your black and female? Are you being disadvantaged by the white female? Because the white female has more opportunities than you.
What if you are gay, black and female? Are you being disadvantaged by the black female and the white female because they have privilege over you? Should you protest them too along with men? What if you are gay, black, female, and ugly? What if you are gay, black, female, old, ugly, short, fat, has poor genetic intelligence and so on. How do you interpret all this?
White males, there are different ranks among them too. Does being a ugly male knock you down on the oppression ladder?
What about ugly, white, poor athleticism and fat. Does that mean the male higher then you is oppressing you because they have more opportunities? Are they apart of the oppressed group too? Is their a ranking system on how oppressive you are based on all the traits you have and don't have? And how do you rank all this? What is considered line of oppressed and privileged? Different people can have a different mix of all these so how do you rank all this? There are infinite number of ways to interpret the world and interpret why things happen. So this would go on and on.
Or are people individuals with many complex things going on with them and can't be grouped by only typical narrow traits like race and gender. People respect individuality, but once it comes to topics about race and gender, individuality goes out the door in favor of a narrow marxist ideal of proletariate and bourgeois oppression mindset.