Because he is.
  1. Yell "YO JAMES FRANCO!" out my window every morning.
  2. Call every hotel and ask if the refrigerator's running and also if James Franco is there.
  3. Spread the word that I'm an "artist" and let him come to me.
  4. Tell everyone he was so desperate to know me he insisted on filming here.
  5. Try to make "Jim Franco" catch on.
  6. Same goes for "James Franklin."
  7. Walk by the set slowly, making direct contact, while telling everybody that he is my son.