Why do Christians insist on saying homosexuality is a choice, when it clearly isn't?

Anyone who is rational and definitely anyone who is gay, knows that homosexuality is not a choice, yet Christians insist on making it a choice just so it's seems it is our fault that we are sinners? Of course they would, God would not be so cruel as to doom gay people from the day they are born, and yet he is, since we are gay from the day we are born.