It has to do with the cause affect between behavior and the creation of social diseases. In modern times, we have all types social mops to prevent and clean up disease. Back when the bible was written, they did not have these things, since they did not have modern science Rather they had to figure out how to deal with the natural cause and affects, between certain forms of behavior, and the creation of disease.
Maybe modern culture could run an experiment for one year to simulate the bible times. We take away all modern prosthetic mops, created by science and medicine, that are used to mop up, after behavior that causes disease.
With all the mops gone, let everyone do their thing and we will monitor disease and attrition rates, to determine which types behavior have the least problems, and which types of behavior have the most problems. This brings us back to bible times and the choices that had to be made to prevent cultures from being wiped out by deadly social diseases. The least problems will be male and female married couples. They will become immune to each other even under less than clean conditions.
In modern times, we can use science to cheat natural cause and affect. This creates a false sense of natural. For example, if you ate rocks this would cause all types of medical problems. On the other hand, say we had medical treatments, in place, for tooth repair and well as all the internal medicine procedures needed to eat rocks. This could become a new fad. It could also sold as natural, since chickens eat rocks.
The medical illusion will convince many this is natural, for a price. To see through the illusion, you need to get rid of the prosthesis, and let nature run its course.
In the bible, lesbian behavior is not given the same treatment as gay behavior, since this does not form as much disease. Natural cause and affect between disease and behavior was the bible standard. The king with many wives, would not sin, if his wives found affection with each other; disease was controlled.
The atheist POV, makes use of the medical and science illusions, which once in place, can compensate for the natural cause and affect. If humans can create good enough mops, is dirtying the floor, as bad as it used to be in the bible? The answer has to do whether natural is important, or whether artificial is good enough.