@dicey I don't think it's possible to explain the disgust response to someone who only has a very sublimated expression of it. That would be equivalent to explaining the color red to a red-green colorblind daltonic. "Yeah i know what red is, it's that yellowish-brown color"
And it's very obvious in how you imminently link it to aggression. People with a sublimated disgust response understand disgust in terms of either aggression or fear by proxy of the urge to avoid or remove the object causing disgust.
Modern medicine and social safety nets allow many people with various disorders to survive past early childhood and semi-successfully integrate into polite society. A child with celiac disease wouldn't live long in medieval Europe, where wheat, rye, and barley made up the lions share of available caloric intake.
The disgust response was similarly important for the pre-industrial man, helping to avoid vectors for disease and parasitic infection, spoiled food, carrion and excrement, signs of contagious disease in other people.
Modern society has progressed beyond the need for such rude things, with a diet based primarily on soybean and corn derivatives, microplastics, and easy access to effective antibiotic treatments.
So today the residents of scenic San-Francisco can walk the streets with extra pep in their step, avoiding piles of human excrement and used heroin needles on the sidewalk.
But we, the legacy humans, the unmutated normals, view you and your ways with a disgust that you could never comprehend. And we wait for the inevitable and already ongoing dawn of the antibiotics-resistant everything.