By that logic nobody would be gay. I have a cousin who I knew the second I met him he was gay, he didn't come out to his family for another few years and they still love him but never talk about the fact that he's gay and are ashamed of it. Sorry but just because you don't like or accept it isn't going to make it not happen. I certainly didn't "choose" to be straight and fail to see the logic in the belief that gay people "choose" to be gay.
Everyone likes to push their beliefs on other people when honestly they should butt the heck out. If they are adults, consenting, and paying taxes then who cares? Seriously, the "normal" family doesn't exist with a mommy and daddy, three kids and dog. My parents have 7 marriages between them, I've had two different step-dads, terrible relationship with my real father, not a great one with my mom and somehow I turned out alright. I own a home, am in a long-term relationship, pay my bills. Stay out of my life and I'll stay out of yours.
Also I'm pretty sure there's been studies on this exact thing and it turned out the opposite, less gay children of gay parents than straight. I really don't see how it matters, is it better if they turn out straight? Are they more acceptable then? Less of a person if they turn out gay? I'm sure we could do studies on how people are raised to believe exactly what their parents taught them, whether it be openess or hate.
I also can't stand the idea that even if you "feel" gay, you should just ignore it and be celibate since it's so wrong in the eyes of the religious right. Might be my complete lack of religion speaking there though. I'm living in sin right now OMG. Difference is I can get married, even with no religious beliefs while gays who do believe in God cannot. It'll change, eventually and there will still be people who can't stand it, just like there are still people who think my parents shouldn't have married because they are different races or believe my father is less than a person because his skin isn't pearly white.