"abhorrent" is much much stronger than "suboptimal for socialization skills".
Besides, every other country in the world gets to have its own cultural identity. The "real world" is very much a collection of monocultures. Only in America is it considered bad to have a cultural identity.
Here you use the term "monoculture." You appear to be using culture and race interchangeably. Clearly they are not the same. Are you referring to monoculture or monorace?
"Asian" isn't a culture. Hell, even "Chinese" isn't a culture. China recognizes 55 ethnic minority groups, plus the Han majority. I'm sure if you put one person from each group into a classroom, you might say "They're all Chinese. Monoculture!", but it couldn't be further from the truth.
A lot of the real world is a "monoculture". Just because a majority of people look similar doesn't mean they all share similar ideologies, experiences, and values necessarily. Race is merely a social construct, and the Asian category covers several unique nationalities and cultures. Black and white are similarly ludicrously diverse. And these are young adults who should be bright enough to seek out diverse experiences and places if it suits them. If Harvard really cared about not being a monoculture they would look at their legacy admissions.
Besides, every other country in the world gets to have its own cultural identity. The "real world" is very much a collection of monocultures. Only in America is it considered bad to have a cultural identity.