i mean, the whole point is that ALL the main characters suck, including the MC. i think shes kind of funny. i'd never be her friend, but i'd watch a reality show about her lol.
also, i'm not sure if its because i've only finished Jeremy and Everett's route and i'm halfway through Nate's but there IS a difference in how they treat you. its very subtle, because they're not going to suddenly become kind and complimentary people. they will always be jerks, they're just currently immature, unrefined, highschool jerks (except Bae ofc, the Antichrist could never be unrefined. he is superior and so adult after all lmao)
SPOILERS!!!
for example, Nate literally has a line about how he likes the MC more than he did before the MC made him talk about how he and Everett became friends. Nate would not be even spending a moment of his busy time with us if he wasn't interested. He's the least pushover-type of person in the group. He tries to end things because he was three minutes late to meet the MC, and therefore obviously not put-together enough to date. The MC teases him before realizing how bothered he actually is and drops her playfulness to comfort him. They stay together obviously, and when she asks if he actually WANTS to end things, he goes silent after all his excuses. Its cute tbh and the most healthy scene in the game I've seen. to quote the scene ending:
MC: "I'm almost glad you were late today. It sure is comforting to know I'm not the only one who falls short sometimes."
Nate: "Yeah, I guess."
MC: "I'll keep your secret if you keep mine. We could be partners in crime." (her secret was jokingly admitting she been late too, as if he didn't know that)
Nate: "God."
Nate: "Okay, I can... accept this. Thanks MC."
MC: "Don't mention it. And I mean that, secret partner."
Nate: "Hah, I won't. Don't call us that."
MC: "Would you prefer 'boyfriend'?"
Nate: "Yeah."
MC: "Deal."
Everett is the most obvious to me, and my personal favorite (though Jerbear is the only one i'd actually date because i'm a miserable mf with chronic mental and physical illnesses). his comments go from genuinely insulting to mostly trying to get a reaction. the insults don't stop because it's basically their love language. they both comment on it towards the end and agree it would be weird to stop arguing. the mf blushes all the time too!
Jeremy even blushes like 10 times total, and so far Nate has gotten really flustered once- like his face was all scrunched in embarassment he MC made a joke about being wet at the beach with him. if Nate is your highest affection level during the year 1 trip, you get a scene where he accidentally cries in frustration in front of you. there's no way he would've done that in front of Bae.
Everett literally lets you talk to his mom!! when you choose to stay with Everett, it seems like he just assumed that was what the MC wanted and is acting like he doesn't care either way. he even opens up about his insecurities and fear of the future towards the end. the only one i can see your point about is Shiloh, and thats because he legitimately might not be capable of being "real."
Jeremy is much more subtle than the rest but not as much as i've heard about Shiloh. Also, Jerbear is literally a germophobe. he wouldn't hold just anyone's hand. he wouldn't make the risk or compromise himself whatsoever without reason.
Anyways thanks for listening to my TED Talk lmaoo