Food habits evolve. Cultures come closer to each other with each passing day. With culture, comes food too. Senior citizens might or might not be abreast with all the new discoveries in the world of food.
If my grandmothers grandmothers.... grandmother eated only the food her granma did and her daughter and daughers daughter did the same thing I may have to change my diet and eat bugs and roots???
Ok, I don't like junk food or even "healty" food with extra vitamins and staff, but all modern food is not bad.