Reminds me of a Black guy I knew in the Air Force who used to cook amazing BBQ spare ribs. He told me when he was stationed in England, he used to go to an off-base butcher shop to buy meat. One day he was in there shopping and noticed the butchers were throwing away the ribs. He asked why, and he was told that they can't sell them because nobody eats them. After that, he would go there every week and have all the spareribs he could carry for almost nothing.
Almost every part of a cow, or game animal, is a delicacy, somewhere, and a not eaten somewhere else.
Traditionally, hunters in northern climates ate the organ meats first, and tossed to their hunting dogs the parts prized by Americans.
It is also true that food tastes, and trends, change. I saw a post by an elderly Englishman, commenting on how oxtail is now sold in butcher shops, and at a premium. He said he worked in a butcher shop, in the 50s, and the butcher used to wrap up the oxtails, and give them free to old age pensioners, because he could not sell them at any price. They even had a codeword for oxtail, so that the pensioners could get them without letting their neighbors know they had been reduced to eating oxtail.