What does Thanksgiving, or lack of it, have to do with homosexuality? God, the Maker of all things and the Designer of marriage, tells us in His Word how homosexuals came to be. In the first chapter of Romans, we read:

For I am not ashamed of the gospel of Christ: for it is the power of God unto salvation to every one that believeth; to the Jew first, and also to the Greek. For therein is the righteousness of God revealed from faith to faith: as it is written, The just shall live by faith. For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who hold the truth in unrighteousness; (Rom 1:16-18)

Many forget that the good news of the Gospel begins with the bad news that men are sinners, and that God is the Judge Who will judge our sin. God's righteous and holy standard of absolute perfection is the rule, and we've all broken that standard (Romans 3:23). The word "hold" is not the sense of containing or embracing the truth. Rather, it is the sense of holding back, holding down, or suppressing the truth by unrighteousness. Paul continues:

Because that which may be known of God is manifest in them; for God hath shewed it unto them. For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse: Because that, when they knew God, they glorified him not as God, neither were thankful...(Rom 1:19-21 KJV)

God is the just Judge of all the earth (Genesis 18:25), and His deserved wrath will come on all of us as we have all sinned. His revelation in creation is "clearly seen" and "understood" by all. How? In creation He is revealed, and ALL can see and know that there IS a Creator and understand His design. It all begins with creation, as those who reject the message that God exists and that He has revealed Himself in His handiwork begin a downward progression that begins with not glorifying God and ingratitude ("neither were thankful"):

...but became vain in their imaginations, and their foolish heart was darkened. Professing themselves to be wise, they became fools, And changed the glory of the uncorruptible God into an image made like to corruptible man, and to birds, and fourfooted beasts, and creeping things. Wherefore God also gave them up to uncleanness through the lusts of their own hearts, to dishonour their own bodies between themselves: (Rom 1:21-24)

There is a progression here that begins with a rejection of God as Creator and Designer of all things, including marriage, and one of the first characteristics of people who reject the Creator is ingratitude. In short, giving thanks is not just one day of the year, and neither is it solely a feeling. It is an action that is critically and inextricably tied to one's relationship to the Creator of all things Who "giveth to all life and breath" (Acts 17:25).