First, b-schools are looking for people with *reasonably* decent quant skills. They're not looking for math geniuses. So long as you can show *sufficient* ability in the math skills dept, they could care less whether you're brilliant (academically) or not.
Stereotypes cut both ways. That's the problem with the "model minority" tag that Asians have - it's mistakenly believed to be a *good* thing, when in fact it's limiting and destructive in unintended ways.
The positive inferences of an "academically inclined Asian" is that he/she is studious, hard working, disciplined, and you know, good at math. We're all supposed to be good at math right?
It's the *negative* inferences associated with it that become an issue. That "because Asians are great at math, the assumption is that they suck at everything else." Or that the academics become immediately discounted or taken for granted because "you're Asian; you're *supposed* to be good at school, right?" Or that the flipside of studiousness is a lack of leadership, a lack of "street smarts" because the image of the overly bookish Asian student is ingrained in academia.
I'm not saying that such inferences are fair or justified -- it's that when you're an university administrator inundated with applications from people from a certain demographic whose strengths are so concentrated in one area, such strengths will get taken for granted especially when the *PRECONCEPTION* is that bookish Asian students have little else to offer beyond academics. And sadly, it's true enough for a good chunk of the "stereotypical Asian" that it makes it easy to paint broad brush strokes across an entire demographic that it ends up hurting those who may have more to offer, but who aren't "different enough" on the surface to show that they are more than that.
Also, it's not about being "unimpressive" academically -- the opposite of "studious Asian" isn't "dumb Asian". That just plays into the self-imposed cultural trap that Asians believe that the primary medium to develop your talents is in the classroom. In plain English, there are many, many ways to be "accomplished" -- but that culturally Asians limit their definitions of that to academics, and see academics and math as the primary (or only) way to getting ahead. "If I need to improve my profile, I'll retake the GMAT." "I need to get a higher GPA." "I need more schooling to get a better job." "If I take a course or certificate in this I will be more marketable." "If I take an exam like the CFA, it will help me." And so forth.
It really comes down to being accomplished in a way that forces the adcom to see you as an INDIVIDUAL, and not as a stereotype or caricature. And that often means having something in your arsenal -- a skill, experience, accomplishment, etc. -- that is not conventional for someone in your demographic. Going against the grain, so to speak.
That's one of the bitter ironies of the Asian-American experience -- that so many go through life with the maxim (most likely drilled in by their well-meaning but misguided parents) that "if I only work hard in school and color within the lines prescribed by convention, everything will take care of itself" without realizing how self-limiting that can be when taken to that extreme -- and that while education is important, it ultimately becomes self-limiting if one fails to color outside the lines - *especially* as an adult.
Racial politics does make its way into admissions -- but not necessarily in as simplistic a way as one may think (i.e. "Asians are held to higher standards, blacks/hispanics held to lower standards, etc.). It's far more nuanced and complex -- and because the subject can get very touchy, a lot of university administrators just don't want to have an honest and frank discussion about it because of the fear of being misinterpreted (or even in some cases, because it's only talked about in shorthand behind closed doors and "off the record" it may be even difficult to admit to one's own views or biases even to one's self).