>>2834806Source where Anno says, "Asuka was meant to be a lead, but she failed?" I've honestly never read anything where he says that.
It's pretty obvious that Rei was meant to be the female lead, which is why so many of the important parts of the story are tied to her, directly. Asuka doesn't even show up in the first few episodes!
Anno also gave Rei that smart girl, good girl, doesn't argue with authority, quiet, Japanese girl personality that other Japanese people always seem to choose for their favorite characters. Much like Ami Mizuno/Sailor Mercury was the favorite character of most Japanese fans, whereas characters with personalities were favored in the West. Asuka was favored in the west for largely the same reason - we aren't as brainwashed into being quiet and just cogs in the machine that don't squeak like the Japanese are, so Rei was viewed by many as cold and weak; she is rarely kind to anyone, nor is she openly mean to anyone. She's is mild mannered, doesn't speak up when people wrong her and acts much like a puppet for Gendou.
Given her trauma and the fact that she was groomed from day 1 to be Gendou's dog, it makes sense she is how she is, but it just doesn't connect with western fans as much as Asuka's in your face, here are my opinions whether you like them or not, "go fuck yourself!" attitude. People tend to choose the character they relate to the most as a favorite - it's not saying, "fuck Rei, I hate her!" it's just saying, "I relate to Asuka more and have trouble relating with Rei."
I don't understand why this concept of being able to like multiple characters is so hard for you guys to grasp.