A big subconscious reason behind bisexual “erasure” is that without social pressure and resentment.. bisexuality is pure upside, and zero downside.
This is intolerable to most people.
It not only negates sexual orientation, it also negates spaces, habits, control and predictability. A bisexual individual often comfortably inhabits both male and female spaces and discourse.
In general, a partner can’t control access to sex, or manipulate using roles, because a bisexual individual is less likely to be tied to gender, role, dynamic or manner. These advantages scale with the individual’s physical attractiveness, privilege and mental health.
The access and comfort with all gendered spaces, and all the subcultures that come under each, defies structural ideas– challenging ideas like marriage and family in a way even homosexuality or trans identities cannot.
And every bisexual suspects with very good reason, based on their navigations of all these spaces, that the true number of them is far higher than other orientations, second only to the “default”: heterosexuality.
The odd thing about bisexuality is that unlike other orientations, you only know its full extent on exploration. If you’re already in a long relationship and in love, only an opportunity for “the other side” and willingness to take it, can bring it fully to light.
It is very easy for an individual person to assume that last 20% of the Kinsey scale is some statistical noise or variance or failure on the test. But for a percentage of them, it is revealing of a much more fluid orientation.
It is probably very much an orientation that in many people can be quiet and “unused” for life. But in many it also creates quiet conflict. And I’m not saying it *has* to be explored. I’m only pointing out the difference in how it works compared to the binary orientations.
It is sad and comical that the stereotype story of a man who fell in love with a woman, married them, had kids and then left because he “turned out to be gay” is framed the way it is. Have you considered he may be bisexual? More importantly, has *HE*?
How much different would it have turned out if he was enabled to weigh his attractions– perhaps as “homoflexible” i.e bisexual? How different and interesting might their relationship or even marriage have been if it had been entered into on those terms from the get-go?
And this is my personal theory, and perhaps an infohazard: it is my view that orientations can be created but not destroyed. i.e you cannot force anyone to be het or homosexual, but context and environment can enable either to be slightly flexible.
Like situational sexual behaviour. Most of the self-control and shame around this and its related phenomena are caused by social pressure. Free of that, this too would exist along the spectrum of bisexuality, and undermine the social desire for more binary behaviour patterns.
TL;DR: To the people who dislike this orientation, bisexual acceptance appears to threaten to create a world where “you can have your cake and eat it too”. Unencumbered by social taboos and ridicule, it provides a natural, scalable social power and flexibility that other orientations and inborn traits do not and never will provide.
And a secretly bigoted gay/hetero person’s response to all this might be resentment. And a trad response to all this might be “yes! this why they are sinful and must be suppressed!!”
But the culture war means nothing to bisexuality. Acceptance can either come slowly, quickly or never. But even in this unorganized, limbo state, its very existence informs and subverts most cultural, gender and sexuality discourse & behaviour, down to individual choices.