Catarrh

With all the various kinds of pickled foods in the world (e.g. pickled eggs, pickled okra, pickled pig's feet, pickled beets, pickled peppers, etc.), why is it that pickled cucumbers got to be called "the pickle" instead of being called pickled cucumbers? Is it just because they're the most popular kind of pickled food? I assume they are, anyhow.