I would hope that the eventual goal of queer activism is not that gay and straight people have equal rights to marriage benefits, employment, adoption and child custody, service in the armed forces, and freedom from discrimination. Certainly all of those goals are admirable and important; but, thinking in those terms just creates further categories of persons that can be potentially limiting. What about bisexuals? What about polyamorous people? What about gender-variant people? While some of these groups might get knock-on benefits from the other equality measures, there are bound to be oversights and misconstructions in doing so.
I actually hope that the eventual positive effect of queer activism is a change in society so that no one is ever bullied for their gender presentation, mannerisms, interests, or romantic attractions; that "gay" is no longer an insult and a synonym for "anything I don't like"; and, for example, that a male who has dated women for his entire life can one day seek out the romantic and sexual companionship of another male without stigma from any corner, nor pressure to identify as one thing or another, and that his doing so is simply yet another option available to a person, like getting one's hair cut or driving a motorcycle.
To put it in more specific terms: the issue isn't so much that sexual orientation is or is not a choice, nor that it is nor is not something inborn, but instead that its origins shouldn't matter because there is no sensible reason (by which I mean scientific reason—but I'd go as far as to say theological reason as well) that sexual orientation or gender identity should be a factor for scorn or discrimination amongst humans.
As I like to say, an adult should be free to share love, sex, residence, and marriage with any and all consenting adults. Why should anyone spend any time trying to stop other people? And why should anyone spend any time trying to argue against the reality or the worthiness of bisexuality, gender variation, polyamory, consanguinamory, Genetic Sexual Attraction, or anything involving someone else’s identity, orientation, or attraction to other adults? Explaining the possible origins of something that makes someone different is not going to get bigots to suddenly stop being bigots. Throwing others under the bus and jumping through hoops will not change bigots either. Rather, we should all be in solidarity with each other and show open-minded people that the world will not end if we have freedom and equality. All of the nosey, judgmental, and controlling people out there should focus on making themselves better people, and being better in their own relationships. Maybe they will when everyone else has come to the side of equality.