I think the people who claim that "the word bisexual reinforces the gender binary because it has ‘two’ in it"are confused — because what they’re actually trying to assert is that people who identify as "bisexual" are "only attracted to men and women."
In other words, biphobes argue we’re only attracted to ONE type of person: Specifically, people who fit the gender binary. That what we find attractive about a person is not their gender but the fact that they have a binary one. (It’s a sneaky way of trying to accuse bisexuals of only being attracted to cis people, although that’s a transphobic argument in and of itself because it makes the assumption that the only people who ‘really’ have binary genders are cis people.)
I think what these people actually need is a more accurate word to describe the person they’re accusing bisexuals of being: A "binarysexual." I would be perfectly happy with people going around saying, "A binarysexual is someone who is only attracted to the two genders that fit the binary — but either one of those binary genders is fine." But to suggest that ALL bisexuals are "binarysexuals" just because bisexual starts with 'bi' is as inane as suggesting that all bisexuals are also bicyclists, bigamists, or bionic "because they start with the same prefix, DUH!"
It’s as much of an intentional misunderstanding of the word "bisexual" as it would be if I said, "Well, technically, pansexual means being attracted to EVERYBODY." That’s what the prefix 'pan' literally means. What differentiates a "pansexual" from a "bisexual" is that bisexuals are sexually attracted to people of more than one gender, and pansexuals are sexually attracted to every person they ever interact with — they’re like the opposite of "asexuals".
The thing about words is they actually mean lots of different things simultaneously. And so people like to try and make arguments from "the definition of the word" but the definition of a given word is not singular or fixed — and the particular narrow definition you’ve picked up on because it supports your argument isn’t automatically the correct one just ‘cause you found it in a dictionary. That kind of flimsy rhetorical strategy doesn’t even fly in 10th grade speech and debate class; it’s sure as hell not a strong enough argument to be a justifiable basis for erasing other peoples’ identities.
In fact, as I recall, people used to claim that being “bisexual” meant that you had TWO PARTNERS — hence all the the biphobic nonsense about how bisexuals are naturally nonmonogamous, will always cheat on you with [insert gender you’re intimidated by], can’t be trusted, blah blah blah. This is just the updated version of that ridiculousness. But plenty has already been written by Shiri Eisner (radicalbi.wordpress.com) etc. about the homonormative political strategy to drive a wedge between B’s and T’s by encouraging bisexual folks and trans* folks to see each other as adversaries competing for the same piece of the Big Gay Pie. So, I won’t go into all of that here.
I guess all I’m trying to say is, if people are really so desperate for an identity that means "only attracted to people whose gender fits the binary" that they can distance themselves from, then let’s give them one: "Binarysexual". And then I’ll challenge those folks to find any bisexual person who that actually describes. Because regardless of what you think the abstract etymology of someone’s identity label means, the actual ways that real people engage in relationships on the ground really matters. I know a LOT of bisexual folks in real life, and I would be hard-pressed to name a single one of them who is only attracted to people with binary genders. In fact, if I had to point to a sexual orientation that, in practice, tends to limit their attraction to binary-gendered cis folks only, you know which one I’d pick? Straight people.
Oh, and then there are all those radfems — both straight and lesbian — who don’t believe that trans women are women, much less potential partners. They’re pretty binarysexual. And gay men who dump their partners when they transition? Binarysexual, too! Hell, there seem to be a lot of them, maybe the binarysexuals need a visibility day of their own.
But that day is not today.
Also, notice how, over the past few years, this nitpicky discourse about the etymology of the word "bisexual" has totally overwhelmed public dialogue about what’s going on for actual bisexual folks. Things like, say, massively higher rates of suicide, homelessness, and bullying than monosexual queers.
Why aren’t we talking about that stuff? Or the more mundane but still importantly relevant day-to-day questions and struggles that are unique to bisexual experience? We never get around to these conversations, because even among community of other folks who are attracted to people of multiple genders, we spend an inordinate amount of time arguing and explaining and defending and defining the fuckin’ word we’re using to say a thing that *everybody already understands what we mean by.*
And notice how the solution that people offer to that problem is so often, "Well, why not just use a different word then?"
Let’s not acknowledge the fact that "queer" doesn’t convey any specific information about a person’s sexual orientation besides that it’s not straight and that it’s kinda political. And that "pansexual", while a lovely and inclusive neologism in theory, doesn’t have the history or culture or instantaneous "brand recognition" behind it that "bisexual", which has meant something for going on 100 years now, does. The concept of"bisexuality" *specifically* threatens both heterosexual and homosexual hegemony in a way that "pansexuality" (at least currently) doesn’t. These words are useful, and even necessary, but not sufficient to replace or obsolete the word "bisexual".
"But there are plenty of other words you could us! You wouldn’t have these problems if you’d just stop being bisexual!"<——- This is literally what bisexual erasure looks like.
Right now, "bisexual" is the most well-known, well-understood, established, and effective word in the English language for conveying the concept of loving people of multiple genders. When we lose that word, we lose a weapon. And, kids, we still really need that weapon. See Also: Higher rates of suicide, homelessness, bullying etc.
Anyway. That’s my rant. (I guess I had to rant somewhere. :P)