I don't particularly love the idea that women who come out as lesbians late in life were necessarily closeted all along. I'm sure that's true for many women, but why is it so hard to conceive of a woman (or a man, for that matter) whose attractions, or choices, change over hir lifetime?(MREWYB is an acronym for my rights end where yours begin; it's a nice enough thought if we must remain within the conceptual framework of "rights," which I wish we wouldn't. Jack has a nice essay on some of the problems with this framework.)
We're always so desperate to talk about sexuality as if it isn't a choice, ever, for anyone, lest we create a crack into which homobigots can insert their argument that it's an American-wrecking lifestyle choice that makes the Baby Jesus cry buttplug-shaped tears or whatever, but, you know, maybe we should be talking about sexuality in a way that says even if it is a choice, people who love and fuck and live with and parent with and grow old with or have one-night stands with people of the same sex are deserving of equal rights because it's no one else's goddamned business and MREWYB.
The whole "it's not a choice" concept is muddled on a number of levels. There's what McEwan mentions, which at a more fundamental level is that this rigid interpretation of sexuality devalues choice in favor of genetic (or whatever) destiny. It sets up a context of unavoidable circumstances and says we're all helpless victims to them--while simultaneously insisting that being thus victimized ain't half bad! Sounds a lot like capitalism when you put it that way, actually.
Another problem with "it's not a choice" is that even if we say that sexual preference or orientation or whatever isn't a choice, sexual behavior always is. The capital-L Lesbians of second wave feminism, for example, could tell you that. It may or may not be personally healthy for any given individual to choose one sexual behavior over another, but it is still possible to choose. Acknowledging this does not lead logically only to the "choose monogamous heterosexuality within marriage!" argument, though if you have a case for it, by all means make it. Accepting that sexual behavior is a choice can lead equally to any number of other arguments, from "do whatever you feel like but try not to hurt anyone" (my favorite) to others just as specific (and potentially harmful) as the fundamentalist line, like "have sex only with people matrilineally related to you" or "never get consent" or "stick with nonhumans." Out of the whole range of options opened up by admitting that there is a choice here, it shouldn't be difficult to argue in favor of doing whatever we feel like short of hurting people, and yet we still seem to be terrified of making this argument.
Another problem I have with the "it's not a choice" crowd, and this is more anecdotal, is that at least among people I personally have known, there is a high correlation between promoting the choiceless concept and promoting the static, often binary (on/off, straight/gay) model of sexuality that McEwan critiques in her original post, the model that doesn't seem to be questioned by anyone on The View for instance.
I tend to identify my sexuality, when called upon to do so, as "gay," for a bunch of reasons. It's a simple shorthand. It is the single word that most accurately reflects my actual sexual behavior as it has occurred in the real world (though "infrequent" also comes close on that front). It has the force of habit behind it, as it's the identification I came to back when I first realized there was something to identify, more than half my lifetime ago now, back when my still-developing brain and still-strong (despite my parents' best efforts!) cultural indoctrination led me to simple answers rather than accurate ones. Because, yes--"gay" is a simple answer, and a decent approximation, but it's not accurate, in a multitude of ways that I'm not going to go into here (partly because some of them are entirely private, partly because it's complex enough that it would extend the length of this essay a thousandfold, and partly because a huge chunk of it is things I haven't even figured out how to articulate externally). I don't know what a more accurate description would be--I guess "queer" would do it, though I have an aversion both to the sound of the word and to the specific people who used it most frequently when I first became aware of it as a legitimate descriptor, and anyway I'm not sure how I feel about using such an enormous blanket term that nevertheless separates all of humanity into the distinct categories of "queer" and "straight," which I reject as invalid.
I think the problem is that the whole notion of "sexual identity" is a crock. It's a function entirely of our socialization in this insane, fucked up, unlivable society we have. It is, in fact, a form of the choiceless victimization I described early on in this essay. Don't get me wrong; there are clearly people who tend towards the behaviors we bundle under the "straight identity" and those who tend towards the behaviors we bundle under the "gay identity" and those who tend towards the behaviors we bundle under the "bisexual identity" and so on, but tendencies do not an identity make.
For a long time, the concept of fluid sexuality confused me; surely, I thought, if you're attracted only to members of the opposite sex, you're just straight, and if you're attracted only to members of the same sex, you're just gay, and if you're attracted to both, you're just bi. Why make it more complicated, more mysterious I thought, than that? Doesn't that cover everything? I eventually realized that the whole concept of "same" and "opposite" sexes is, at best, incomplete and inaccurate, that the "attraction" model isn't much better, and that there is a great deal more to sexuality than just which side of the artificial gender binary you most enjoy mingling genitals with.
Earlier, when I said "sounds a lot like capitalism!" it was more than a jokey throwaway. The late-period capitalism that we live in requires of us that we feel like we have options--but only the options provided to us by the system itself. Thus, with sexuality, we do have, in many ways, a greater openness than the generations that preceded us. It's OK to be gay, pretty much! But this openness has been channeled into tiny little boxes, easy to control, easy to market to. Gay? Buy the gay identity! Straight? Buy the straight one! Look at all these options we have for you. Anything you could possibly want to reflect and display your identity, we can sell you. And if you want to choose some other option--sorry, it's not a choice.
I've said it before--just as economic interests seek to control our movements, a control that can be fought with the Situationist concept of psychogeography, the same interests seek to control our sexualities. We need, again and always, to be sexual flâneurs--in, and this is important, whatever way best suits us.