The obvious answer is because they are tasty and people are used to it and it is ingrained in the very culture (cooking, traditional holiday meals etc) of prett

The obvious answer is because they are tasty and people are used to it and it is ingrained in the very culture (cooking, traditional holiday meals etc) of pretty much every country I know of. Those are some of the strongest forces working in unison. Seems very unlikely hamankind will ever move off animal based diets.