Because I reject the various false premises scattered around in there. I don't think God is responsible for anyone being a homosexual, don't think He infected anyone with a desire to sin at all and reject the wicked notion that He is malicious. So I have no answer to your question other than to reject the question as ludicrous. And, frankly, evil.
Well, this was my original point …. the one you were so quick to insult me about …. that a lot of Christians are not willing to face these difficult questions, because in doing so, they will have to face their own self-righteous over-simplification of "sin", and perhaps give up their well-trodden habit of judging and condemning others for their "sins".
And here you are, also, denying the evidence of science and the witness of homosexuals, themselves, because you just can't face the questions that their genetic inclinations imply.
If you accept the notion that homosexual desire is given us by God and that God declares that desire to be evil then you'll either have to plainly accuse Him of evil or explain how in the world He's not.
I can easily explain how "He's" not.
The genetic inclination toward homosexual attraction is a part of the natural design of human existence. If we believe that God is the creator, sustainer, and author of that design, then God is "responsible" for a significant percentage of homosexual desire (not all, as clearly some of this desire is the result of cultural and experiential circumstance). This is a logical 'truth' that we can all see for ourselves if we are willing to look.
On the other hand, we have a religious book written by men who had no access to the scientific process, and a limited grasp of logic, who concluded for themselves that homosexuality was an "abomination" and said so in their religious writings.
I think the answer is clear, here: that as time has passed, we have come to recognize that homosexual desire is a part of God's plan as it is being expressed through the mechanics of existence, while the condemnation of it by ancient Hebrew writers was the result of a bias based on the limitations of their time, place, culture, and intellect.
That leaves us with the greater question of our human inclination to "sin" in general. Are ALL human inclinations bio-genetic, and therefor unavoidable "sins"? Are we still all being held accountable for them according to an irrationally malicious God? And I think the answer, here, is also quite clear: no, and no.
We are born with genetic inclinations, but we can learn to recognize them within us, and we can practice at diminishing their hold over our minds and hearts.
We are also socialized into some sinful desires and inclinations that we likewise can eventually learn to recognize and practice at diminishing their hold over our minds and hearts.
The "sin", then, is not in the inclination or desire itself, so much as it's in how we respond to it, internally. Are we trying to recognize our sinful desires for what they are, when they occur? Are we working at not allowing them to own our hearts and minds, and dictate our actions? Or are we just excusing or justifying them? Or worse, even reveling in them?
It's in how we deal with these inclinations, internally, that will determine our sinfulness, not in the fact that they exist in us. But that's something no one else can really judge, isn't it. We can't look at another person and know, really, how strong the God-given inclination to 'sin' is, in them, or how honestly and stridently they are trying to deal with it. So that the truth of the matter is, that we can't judge the sinfulness of others. Because we can't feel what they feel, or think what they think in reaction to it.
But there are a lot of Christians who don't like this fact of our reality. They WANT to stand in judgment of other people for their sins. They WANT to play God, and condemn people to hell for what they think is their unrighteousness. It makes them feel strong, and good, and glorious, to do so. And this is what's fueling their bigotry against homosexuals. And it's what's fueling their (your) persistent denial of the idea that God would 'infect' people with the inclination to sin, and then condemn them for reveling in that same inclination. Because that's a complexity that they don't want to face, as it eliminates their own imagined ability to pass judgment on others, and play God, themselves.