When a work of art exists for a long time, there just comes to be some sort of "commonly accepted perception" coined by earlier generations of fans (or just the loudest among them) about how the characters, events etc. are to be seen which a fresh viewer wouldn't necessarily rely on by themselves. Often, they contain gross oversimplifications of treat as "necessary" interpretations that aren't necessarily obligatory confusions.
When it comes to Evangelion, part of it is that whole "Anti Otaku revenge rant" misconception that attributes this strict cynical "index finger-y" tone to what's actually a pretty autobiographical work about the author's struggles with & reflections about his own shortcommings. He's a giant nerd himself and has said on record that he doesn't think there's any bad about being an otaku per se or anything, but he's got a certain self-awareness and is really talking about the pitfalls of sticking only to one niche in life while blocking out everything else.
The thing with Rei in particular is that Anno's got this weird disconnect toward her as a product of his subconscious and the usual shy artist's "I'm surprised anyone likes it" attitude that her toward the whole of EVA - That doesn't mean that she was meant to be a "mere creepy plot device", indeed in the same interview that's often cherrypicked to say he doesn't care abot her, he describes her as coming from the "purest, most core part of [himself]" - to an extent, Rei is/embodies/manifests/symbolizes that 'weird disconnected detachment' with whom her creator regards her and presumably, parts of himself.
I find it ironic that an argument that claims to speak for/about "real women" reduces Rei to some trap for Shinji to fall into, instead of a complex character with interesting sci-fi concepts and a moving character arc that is, at it's heart, about finding a little bit of breief, transient human wamrth, contact & meaning even among the barest or harshest of circumstances. (wether you read it as vagely shippy or friendship doesn't really matter that much (though you could IMHO make a good case), but, the point of Rei is that she's her own person even if very little of what she is is actually her own, not even her face, & even her very soul is something she only "loaned" and will have to give back. ) - That's not , there's a published thing out there of her VA discussing the whole "universal human feelings" aspect of it and documents detailing that Anno's primary directive as to what she was meant to come off as was "a bitterly unhappy girl with little sense of presence" r detailing how there was a theme about communication (relating to how he splurted too much of it out in ep 6 and felt he ran out of ideas for a while after that)
- indeed the one time she's outright assigned a significance, she (and Kaworu) are characterized as "The Hope that People can Understand each other". That's what they are, some good experiences that were short, and full of unfulfilled potential & ended painfully, but they're a proof of concept that understanding & positive experiences can happen, so that Shinji ends up going back, hoping that good things could happen again & ending up thinking back of all the good moments he had with them... and the whole rest of the cast, (c the "group photo" shot)
One has to be pretty cynical, or have an agenda in mind, to think that Rei is "wish fulfillment" just because she actually cares about Shinji & vaguely shows it now & then - She never cushions Shinji with the brutal honesty, tries to make him consider possible reasons NOT to go through with TI ("then what is your heart for") and often serves as a partial motivation to get him to do things he otherwise wouldn't dare, both and interpersonally (probably because at least at the beginning, the convrsation just wasn't gonna happen if he didn't take the initiative) and with her whole "raised in a lab & barely known how to human" presents a pile of baggage no smaller than Asuka's, they've compared her to being a bit like someone indoctrinated into a cult - indeed she's right there with Misato & Asuka in the Pre-Instrumentality montage about they all have complexities he can't ever fully predict.
It's not like Asuka is so "realistic" (Child Prodigy Ace Pilot with college degree, also super popular & good looking - plus, the idea that a girl who talks trash about you really has the hots for you & secretly all vulnerable?) - This isn't to say that "Actually Rei is great and Asuka is trash" but to show how arbitrary this argument is - It's a work of fiction, so it's stylized, exaggerated and metaphorical in order to underline a message. That's true for all characters.
Is the concept of a socially inept, lowkey philosophical solitary schoolgirl who also has an impressive determination and a sweet & caring side once you get to know her really that un-relatable and inhuman? It's hard not to take personal offense to that one.
It's true that Asuka is in most of her functions relative to Shinji, used to represent "the harsh realities o human coexistence" - but that's just it, coexistence, not-killing-each-other. Having to live with her =/= having to bed her.
If anything the fact that he has teenage lust for her is there to enhance the "hard to coexist with" aspect - after all it's easier to dismiss someone's criticism if you don't give a crap about their opinion, but we are drawn to other people & have to deal with rejection as a result - She's basically made to be the worst possible match for him, someone that he fails & dissapoints & doesn't understand, painfully similar in their headups and incopmprehensively different in their priorities, someone who forces him to deal with rejection... Like, it's not that I can't see how for some people this might make a ship here interesting b/c of this whole "opposites attract" hogwash, but in the end, she's also a character with her own story & themes, not some truculent baton meant to deliver the just punishment for Shinji's wimpiness, which is what this argument basically makes her out to be - What about her motivations, responsibility for her actions & consideration of what would be good for her?
Yeah, relationships are sometimes work, but they shouldn't be constant torture - in the first place, the "work" part is something you have to deal with if you want the good parts. Why pick the most difficult possible option? Like, I can see why a fanfic writer would do that or how some might see it as interesting but it's by no means "THE ONLY CORRECT ANSWER". They're all pretty young anyways, for all we know Shinji could end up married to, say, someone vaguely like a more toned-down version of Mana, or some dude he meets in his 20s, but ppl are gonna be more interested in reading something with the prexisting characters that's just this implicit rule that everything big and relevant is expected to happen in the part of the characters' lives that the camera is pointed at.
In the end both girls are associated with a lot of symbolistic dichotomies, but it's not some sort of clear-cut "negative/positive" split, they're both way more complex than that - This isn't about correct or incorrect choices but about the sometimes conflicting sources and desires affecting the human condition. Like, even if he got together with one of them the other would pobably wind up being an important friend.
As for Ikuhara's comments, that's just Anno talking about a reaction he got from someone else, and the idea that "getting married and pregant" equals a "real" woman is kind of disgusting - Like, I get that it's in part just what we'd call poor word choice today and that he's really just talking about fanboyery in general and the whole purity complex, and how in 3D land people get old & gross biological stuff happens but that's demanding this one character be "sacrificed" to give a finger to a societal phenomenon that doesn't really have anything to do with the original intentions for her... Wouldn't poppin out babies make her more of an "idealized wife" or whatever? I get its meant to spite this toxic purity complex thing but that's not the only possible reason people like her - she's ultimatel someone who had a short, unrealized, possibly doomed existence that was eventually cut short and couldn't attain that sort of normalcy excepts in the brief moments that she vaguely bonded with some of her peers.
Like, dismissing such moments as "subservient fanservice" seems to painfully miss the point, she comes from this world of big concepts and shemes that she's subordinated to & starts out pretty disconnected from the people around her or even her own physicality, anything you'd term "everyday life", so experiencing some of that mundane stuff is a learning experience there.
And I know an eighteenth charm, and that charm is the greatest of all, and that charm I can tell to no man, for a secret that no one knows but you is the most powerful secret there can ever be.