I think some folks really have an exaggerated notion about the benefits of labeling oneself a 'minority'.
You haven't looked into affirmative action at universities, then. Labeling oneself as a certain ethnicity is the equivalent of adding 100+ points onto an SAT score in ultra-competitive admissions processes.
Also, from my own personal experience, I was involved in the process for hiring law clerks in the New Jersey judiciary. Judges were pushed to hire minority candidates. Every year, a blue paperback book was distributed with the names of candidates who had either self-identified as being in a minority, or who appeared to be a minority based upon certain very unscientific factors (such as name... thus, how the judiciary ended up with white law clerks named Cimmerian and Winifred... somebody thought those names sounded ethnic.)
Affirmative action is such a messed up situation. It literally only looks skin deep, when not all minorities are similarly situated. Rich black kids who go to elite prep schools will be given preference over a dirt poor white kid with better test scores. That's bad enough. To play off those stereotypes by claiming minority status when you're an upper class white woman is beyond the pale, though.