I believe that no one has the right to limit the scope of creativity.
Artists have an inherent right, if not duty, to explore, investigate and research any concept, subject or theme. This includes art about art, about advertising, about photography and original images created by other artists. (This does not include forgery or intentional deception of the viewer)
Once these images are created and exhibited or published, in my mind they enter the public domain and like everything else become potential subject matter for art. Surely, if art mirrors life, then art itself becomes a part of life and open to interpretation and re-interpretation.
Today we live in a consumer society in a sometimes abstract and artificial world. Art is a part of our world, culture and society, and many artists and writers (and film makers and architects etc.) do quote, sometimes very directly, art of the past as they participate in the present and contemplate the future.
Copyright laws cloud this issue but are, and always will be, challenged.