The white American discomfort with non-muscle meats is a direct legacy of slavery and white supremacy.
Pre-industrialization, it made no sense for any culture to find any cut of the animal “gross”. Animals were consumed by the local community that slaughtered them and every animal comes with the same set of brains/livers/eyeballs/blood etc. which meant that every community had their own local recipes for brains/livers/eyeballs/blood etc because everything from the animal was too precious to discard.
However, on a ~1000lb cow, you might get ~100lbs of beef chuck but maybe ~2lbs of beef eyeball and ~10lbs of beef liver. What this means is if you take an expansive view of all global cuisines over all of history, in almost all cultures, the organ meats are typically prized above muscle meats and are considered delicacies accorded to the highest status members of the group, simply because they’re much scarcer.
It wasn’t until the white genocide and settling of the Americas that land became abundant enough that the average ordinary person could expect large amounts of meat at every meal and the ability to be selective about what meat they chose to consume. For the first time, you had a vernacular cuisine in which certain parts of the animal could be thrown away or fed to the dogs or otherwise was deemed not fit for human consumption.
This, coupled with the introduction of institutionalized slavery led to a system in which the parts of the animal were split into “white meat” and “black meat”. The scientific racism of the time back derived why certain parts of the animal were white and black. Black meat was “dirty” because it touched the ground, white meat was “clean” because it was “high on the hog”. Black meat was “gnarly” because it had bones and tendons and fat, white meat was “pure” because it was large, lean muscles. It’s important to emphasize how much of this had nothing to do with the culinary value of those parts but because it served as a mechanism to uphold racial hierarchy.
The long legacy of slavery means that we still uphold many of those same values today even though they’ve been totally divorced from their original context. What’s more, the centering of Whiteness means that, even today, we view discomfort with offal as “normal” and cuisines that relish offal as “weird”, despite offalless cuisine being a tiny minority in both population and time. You see the same thing with, eg, insect eating which, despite being practiced by the majority of people worldwide, is viewed as a gross and aberrant practice by Americans because the people who eat insects tend to be poorer and darker than the people who don’t.
PS: This information was primarily sourced from Odd Bits: How to Cook the Rest of the Animal which I highly recommend as a great cookbook on all sorts of offal!