I'm guessing how you started playing this game has alot of weight in the conversation.
Let's say someone who started from Episode 01, they waited years with Maya going nowhere, that's why I think that the Maya Haters are so vocal about it, years of getting blue balled.
Although I disagree with you, in a sense that I believe every main girl (Maya, Josy, Jill, Sage and Bella, with a wild Quinn joining in the latter chapters) is a valid Life Partner for the MC, I do believe some would be more dificult than others.
1) Maya: Personal Opnion: Maya is Bae; For real tho, she doesn't sound like a fair investiment. She is a lesbian, that is trying to not be one, in the Trouple the Protagonist sounds like a +1 in the relationship of Maya and Josy, not like an equal partner. He just so happens to be the novelty in their relationship.
2) Josy: Personal Opnion: Not bad; Josy I believe is the most vanilla of all the options, she has the second (third) best scenes with the MC (behind Sage and possibly Quinn), is essencially a stranged bisexual girl, that found love with someone else (the MC), she definetly doesn't feel like a Lesbian (i.e. Maya), sometimes she comes out alittle bit strong, which makes some guys in the forum call her Goldigger (tho she is digging Gold on the poorest guy on campus).
3) Jill: Personal Opnion: She is very Wholesome. By far the most wholesome character in the Novel. While the early chapters everyone and I mean everyone was kind of a dick (Maya & Josy were Liars, Sage was Manipulative, Quinn was just an Asshole, The Diks were Dicks, Bella was just Angry) Jill actually gave Holier than Thou vibes, that is why I though it was just a Front, but I was glad it was not. Possibly the Best love interest for the MC in a real World, but this isn't the real world.
4) Sage: Personal Opnion: She is the Hottest. As is concensus in this forum, Sage has the best scenes by far. She has a rough start with the manipulation of the Protagonist, but she starts getting better with age. The Guitar classes where really nice to complement the relationship between the two, and the MC taking care of Sick Sage, was just wholesome. Definitely understand why she is the favorite of most people. Oh, and she is a Redhead with fucking freckles! Personality wise she was more developed later, showing why she is dismissive of her duties as President favoring leaving her VP to do most things. But it seems that she is about to come back to her duties with Maya, setting up a confrontation with Quinn that I feel is necessary for her character.
5) Bella: Personal Opnion: I like Bella, but she is weird. Like there is way too much weird shit going on here. Like she is trying to see if you are fit to date her BFF by jerking you off in the shower? Like granted she does manage the MC's wild side which is a Huge Plus, but let's be honest here, there are alot of variables on the table. Is she Stranged or just a widow? Did she lose a son? Did she have an affair with Jill or Lana? I feel that we gotta see alot more of her before a better judgement can be reached. That said some people are going mad crazy with the theories: Serial Killer Bella
6)Quinn: Personal Opnion: A fixer Uper. Quinn has two big advantages: a) She is an underdog; b) She demands a Redemption Arc. Quinn is someone who started being the most Obnoxious character in the game from Chapter 1, but hence has received the most development. In the latter chapters we see the origin of her perils and are led to sympathize with her. She doesn't start as a love interest, but as an antagonist, giving her a completely unique point of origin. Her uniqueness is further developed as the Author shows us that Quinn has had feelings (prolly carnal) for the MC since Chapter 01, but is incapable of demonstrating said feelings in a normal way due to being made amoral. She cannot see why what she is doing is wrong, but she can sure as hell feel it, as it shows in her facial expressions in the latter Episodes, with her becoming increasily nicer to the MC, as if seeing that her Tease and Push strategy wasn't working. Her biggest hurdle tho is the Drug business, one of her traits is being a Drug-dealer and a Pimp, the Pimpin is easy to fix since it's an Amateur Ring, but there is no such thing for Drugs, you are a slave to your supplier, there is a saying: "you don't meet former drug-dealers, they are dead or in jail", for the MC and her to Work she would have to leave her past life behind, and that would require alot of work, alot more than any of the other girls that can be seriously considered Main LIs, I fear that her ending might be a sad one, where she puts herself and the Protagonist in a situation of no return. That is why although I like her evolution as a character and hope the best for her and her fanbase, I feel scared of the direction DPC can take with her, as she losing everything and dying in a gutter somewhere is a possiblity.
Sorry for highjacking you comment like that. I feel you made good points, and I just wanted to insert my opnion on those points myself. Still Riona is Best Girl, someday the MC is going to make her cum, but while she isn't a LI, I settle for M&J followed by Sage, Jill&Bella and finally Quinn, although I like them all, and don't feel negative towards any of them.
Karen and Sally need an Expansion if you know what I mean.