If it is legit, and backed by the actors, approved by WB, etc., why do they need a petition?
ETA: and if it is 'inspired' by SPN and set in the SPN universe, they would never be able to reference the Winchesters or Castiel, Rowena, etc. anyway. So basically, they are trying to get their fanfic to air, in hopes of being supported by the 'audience' that might recognize it as SPN, a show that is pulling in a bare million viewers at this point. Yeah, Netflix, get right on that would ya?