God made all things good, but through the fall, countless deviations from God's intentions have prevailed. These were not the intentional will of our Creator, but because he gave man choice through which he sinned and continues to sin, they became the permissive will of God. He permits us to sin in spite of its consequences. All of us have inclination toward sin and all do sin. This does not mean that, because all of us are tempted to sin, we succumb to each temptation.
Some temptations are stronger than others.
God made provision for sexual fulfillment within the framework of marriage. No such provision was made for same-sex fulfillment. It is not the intention of God that there be sexual expression, whether heterosexual or homosexual, outside of marriage. I am not qualified to judge whether homosexual desires are inborn or developed. As for myself, I don't think that I could have developed a sexual attraction for another man.