I don't claim to be able to answer for God, nor do I feel I need to; however I believe that this logic of "God allows it so it must be OK" is highly fallacious.
First of all, you decry the focus on sex rather than love, when--as I've stated--homosexual sex is (in my reading of scripture) the only act in a homosexual relationship that is inherently sinful. Also, it should be stated that Paul mashed a point of sing that those in the church have no right or responsibility to judge those outside the church, but only those inside. So while I find homosexual sex to be sinful--just as I do premarital sex, adultery, violence, deceit, greed, gluttony, wrath, etc.--I don't judge people for their sons, because it's not my place to do so.
Now as for the question of "why are gay people born that way?"--I can only assume it's the same reason that some babies are stillborn, some are born with disabilities or chronic infirmities, some are born with mental illnesses, some are born to mothers who die in childbirth, some are born in abject poverty with no prospect of relief, some are born into families full of abuse and alcoholism, and some are born orange with pompadours and tiny hands. This is a fallen, sinful world, and many things happen--while still inside God's sovereign will--outside His original perfect design, because humanity brought sin into the equation. The fact that something exists in the world God created does not necessarily make that thing good in and of itself. So no, I cannot take the notion of people being born gay as God's tacit approval of homosexuality. Otherwise, people being born sinful (as scripture indicates) would equate to His tacit approval of sin, which is simply silly.
Regardless...my reasoning for my beliefs regarding homosexuality being what they are, I still fail to see how they make me "intolerant" (the original thrust of the discussion), when I don't treat gay people any differently than I do straight people. The only thing I'm intolerant of is (as proscribed by scripture) a willful persistent unrepentant adherence by a member of the church to a sinful lifestyle, and that isn't limited to homosexual sex.