On paint and the paint surface

Since Van Gogh, if not Constable, painters have often concentrated on handling paint with a self-conscious flourish which privileges technique over what technique is there to convey. This trend is contrasted both with the kind of 'finish' associated with Ingres and Salon art and with the practice of older masters such as Titian and Rembrandt. Why do so many modern painters, from Vlaminck to Hodgkin or Auerbach, insist on their own painterliness? (Examples cited are mostly taken from recent exhibitions.)