I think that the moral reason all divorce pleas should be granted is that no one, gay, straight and all conditions in between or over, should be denied the ability to seek a lifetime loving partner, wife or husband, for any reason.
If Jesus is/was seen simply as a moral teacher, it could be argued that though He may not have been wrong for that cultural era, His wisdom is wrong for todays world. Keep in mind, however, that marriage is a sacrament and that although it is always a persons right to seek a lifetime partnership, the very idea of marriage is a symbol of having made the choice. As a legal contract, marriage can be ammended at any time though some would argue that as a contract it should be binding and not at all easy to simply violate.
If a Christian, even if you become convinced that Jesus was indeed wrong, it would not make any difference to you because you actually follow tradition, culture and your family’s inherited traditional God. Not really a God that you selected through trials of his moral character.
Many Christians believe that God existed long before we were born and that it is He whom selected us rather than us creating Him in our own image and mindset. It is good, however, to bring up the idea of tradition and culture. If Jesus is the eternal Son of God (Gods character manifested in human flesh) the question to ask is if He would change as cultures and traditions change or whether He would be a rock in the midst of societal and cultural change.
I see that as anti-love.
Does love originate from within our souls/minds or is love originating from an external source---in communion with us?