People were forced into sexual relationships - or often raped - by others merely because of a humanly constructed social status. If that was Paul's perception of homosexuality, there is no surprise that he would condemn it. Looking at people as property is wrong. Rape is wrong. Feeling obligated to subject oneself to someone sexually because of his or her social status or net worth is wrong.
But if St. Paul saw what existed today, I'm quite confident he would not write the same words again. If he saw loving relationships between two men or two women who loved each other and wanted to experience life together, I think he would see that merely as another expression of God's love.