In what way is that similar? A beautiful, blonde haired, blue eyed, aryan woman is probably one of the finest human beings on earth. Simply because it combines genetic traits that work together very well and look good. There is a reason why leaders of all nations throughout history wanted to be displayed on a white horse, instead of a regular brown one.
Simply because a white horse is much more beautiful and seldom than a brown one. Nobody questions wether or not that horse is much more fitting for a leader of a nation, simply because everybody instantly sees it that its genetically superior, alone from its looks. Therefore to be attracted to a human woman that has similar traits, that are sought after between humans its just common sense to see that human woman as attractive.
While cuckolds literally have to do mental gymnastics to justify their "fetish." Like its not even a single trait that makes them attracted to it. I can kinda understand people who are into say beastiality or something. Maybe fur turns them on or they like the smell of certain animals, makes sense. But cuckolds? Cuckolds need to put themselves into that kind of situation and it can't be just any situation, it has to go a specific way for them.