>>3070629Rei's personality isn't derived from Yui's.
In addition, people like Asuka because she's more or less a meme and it's the "safe path" for insecure beta otaku to take - it's the director's favorite. If you pick the same character to champion as the director likes and protects - how can you go wrong?
Consciously or subconsciously, this is the mindset of these people. Even non-Asuka fans, but self-proclaimed "big" Eva fans might come to champion Asuka precisely because they parrot the opinion of Anno, in fact defending him.