Rama
It's like with every other love interest, whether it be animated!Steve, that cop, or Nemesis, writers feel like they have something to prove with that character, and they either build up their character (STEVE OUTFIGHTS DIANA!) or knock Diana down a peg (NO POWERS AROUND TOM!). With Rama, Luke doesn't have to prove anything because he's already equal to Diana, so Rama gets a personality and a character instead of macho BS.
Look at how HAPPY Diana is to find out she's real! D'awww!