I love pickled tongue. My Mom made it often. It was much easier to peel after she pressure-cooked it. We could hardly wait for it to pickle before we talked her into cutting off slices for us. Yum!
Thinking about the current foodie interest in umami and organ meats, I believe our current meat supply has been bred to such blandness that people are desperate for the satisfying taste of red meat.
I have noticed something similar in people who eat properly prepared venison for the first time. Just the odor of the raw meat is so iron-rich that it is noticeable.
All these meats are really low fat, as well.