Why? Some art is purely representative, some is abstract, some is narrative driven, some is not. There is 'chaotic' abstract art - like Pollock - and regular e

Why? Some art is purely representative, some is abstract, some is narrative driven, some is not. There is 'chaotic' abstract art - like Pollock - and regular examples - like Escher or Vasarely - and many points in between. Why should using a rand function and a line/point shape be fundamentally different?