Lolwut? Liara was arguably the most central and plot important squadmate of ME1. Tali is also required, gets you the recording and makes your career as a Spectre but then gets a mere optional sidemission (geth incursions) related to her after it, as opposed to Liara finding Ilos, being front and center of every post mission debrief if you recruit her early, and getting a plot mission practically tailored to her relationship with her mother(Noveria). Meanwhile her romance arc was pushed far harder than the other two for both sexes of Shepard (large portions of her convos are devoted to how asari have sex, with her blatantly expressing interest in doing so). Then before ME2 came out, she got an entire comic series with 4 issues centered around her (Redemption), and the rest of her core role to the franchise is well known so no need to elucidate on it.
Ash though a required squadmate was hardly plot relevant (not at all if you played a female Shepard), never was fleshed out in any non game media until a single issue of 2013's (post ME3) Foundation, and was basically forgotten as a character after ME1 anyway (Horizon and "good to see you" in the following games, respectively). Miranda was never really core either. She is a plot important and mandatory squadmate in ME2, sure, but is just 1 romance option for a single sex among 2 others, can be killed off within her own game (albiet it takes an essentially deliberate effort), then becomes a Flanderized caricature with barely any attention given to her (except on more arseshots) after ME2.
I think you misunderstand me. By core, all I meant was 'around since the start and playing a role in that'.
Liara can be recruited over 1/2 way through the game. As well, she can be involved in only Therum as someone needing rescuing. I hardly consider that core. I consider that as involved with the main plot. You do speak with her after missions, but again, this can only be once or twice if you pick her up after Virmire.
Miranda however is part of Lazarus Project, part of Freedom's Progress, a more constant reference, has her Loyalty Mission (that has more to do with the overall design of the game though), and her special line if brought on the final battle.
Liara in ME3 however is part of both Mars and Thessia (and From Ashes if you include that, though DLC), also a more constant reference like Miranda, and she's very hard to keep out of your story.
I also consider Liara to be the most plot important squadmate in ME1. She just doesn't fit my definition of core. You can go Eden Prime, Citadel, Feros, Novaria, Virmire before even meeting her, and only hearing small mention of her. But I do consider her a very close second, if not the first, if there wasn't for this huge factor.
In terms of the comic stuff etc, I was only talking about ME1 in isoloation. When it comes to the whole trilogy scale of things once we got to 2012-2013, yes I consider Liara the most core squadmate, not just for females, but overall. I just think ME1 didn't work as much with that assumption, nor did ME2 even, again in isolation. I feel Liara is the pushed once for ME3 and the trilogy players, not so much if only playing ME1 alone, or ME2 alone.
I reiterate - you're talking in longer scale franchise terms when all I meant was for players (often new ones) playing a single game without any connection to others. You're talking about all sorts of secondary media like Foundation instead of just ME1 alone. In ME1 we pick up Ashley and we have her throughout the game and we keep getting her input until at least Virmire (over half way through game). In ME1 we don't have Liara, and we don't get her until at least approaching half way through game (if Therum is done first). Liara CAN be tied into the story the most, and she is ALWAYS arguably the more important character of the 6, not even just compared to Ashley. But she's not the consistently 'core' character you get and probably keep. You can minimize Ashley but she's almost always around. You can minimize Miranda but she's almost always around. You can minimize Liara in ME3 but she's almost always around. Similarly, I consider for example James and EDI to be pretty core to ME3, even if their importance is relatively minimal to progression of plot (they get their single or multiple highlights, but they don't push most of main plot forward). Because they're always around and always *involved*.
Again, core to me doesn't = importance. It can mean that, but I err on the side of it meaning 'central to game design', not 'of import to plot'.