Bisexuals are not interested in polygamous relationships or threesomes. Further, it has nothing to do with wanting attention. Bisexuality simply means that an individual is attracted to both men and women. Bisexuals on Emory's campus and in the country at large are, for many reasons, a silent and invisible population. Since there is no cohesive bisexual community either at Emory or elsewhere, bisexuals are less likely to identify strongly in terms of orientation.
People deal in dualities.
You're either old or young, tall or short, gay or straight. Addressing the middle ground usually causes problems. Coming out as a bisexual is just one more example. Some people talk about it as if it were just a phase a sign of disturbed childhood or a need for counseling. On the other end of the spectrum, it is often treated as a cop-out.