That is a great passage, thank you for posting it. And yes, going by that; we would be morally equivalent to homosexuals. No one is with out sin. Once you dwell into the bible, there isn't much of anything that we do that isn't a sin.
Maybe the point is NOT to fixate on things being a sin but to celebrate the Creator by properly adoring His creation. You weren't created to walk around in sackcloth and ashes. Beauty was the first order of creation.
If someone objectified a work of art by Rembrandt with such shabby disregard as to cause the oils to smear and smudge would would rightly curse that man as a savage and drive him from our midst. And yet, the Creator has ordered a universe that brings to us beings of beauty and gentleness and affection that Rembrandt can only dimly capture that magnificencse after years of study. But when it comes to the actual living, breathing, thinking, feeling woman that is the archetype for that magnificencse how many would have no care for her except to ejaculate, wipe-off and send her home?
It debases her, the entirety of Creation and mocks the purpose of the Creator.
How can that NOT be a sin?
What if, instead, she was cherished by human eyes with the same adoration as her Creator? Would there be room for mere lust or would you rather fall at her feet weeping rather than commit any offense against her?