Because amongst similarly qualified candidates we are THEN allowed to differentiate. It's the same reason you may pursue extracurricular and then put them on your college resume. Differentiation.
Where's your crocodile tears for Vietnamese kid from south central (where the Vietnamese in America are on the lower end of the economic scale) who is admitted to Harvard instead of a Chinese, Korean, Japanese, or Indian kid from a well to do family? Lets segment Asian Americans and see how you feel.
When opportunity is equally earned, we can then look to representation. Your argument is just an attempt to claim all spoils.