Fast food can have no taste. No taste is the only taste that appeals to the masses. Fast food can't risk the cinnamon, garlic lamb kabob or the spicy mango chutney. These tastes are too specialized. They won't appeal to the masses. Ditto for movies, books, shopping and every other staple of our mass culture. Ditto for ethic.
Its problem is that it's bland. It offends (almost) no one. Offers no hope for the future. Carries no satisfaction; no higher calling; no inner solutions; inspires no one.
And worst of all, captures none of what we subliminally recognize as the greatest human endeavour: love.