Not what I meant to imply. And what I said was in jest. I'm not expecting the tragedy that befell her to have been her fault. I just feel like the story is much better and much more meaningful if she stays gone.
That said I don't have much sympathy for her. From the flashbacks we have seen, she was an absolute asshole as far as children or teens go. Can you imagine how much of a bitch Nami would have turned out if they had remained friends well into the late teens/early adulthood? I don't think the "hate" she gets here is unwarranted. She is portrayed in a ratherawful manner.
The hate's unwarranted. The flashbacks that have been shown up to this point don't paint that kind of picture(that she was an asshole). The most a-holish thing she did was... what? Playing MC's video games knowing that it would bug him and get his attention? She was a kid. A kid with a crush. Most of the "bad" things she did were done in order to get MC's attention. In literally every other flashback not-involving her going after MC, she's a sweetheart. People hate her because they've either already chosen an LI and dislike the prospect of Summer potentially ruining things for them, or they dislike the prospect of her returning at all. She hasn't done enough to justify the amount of hate she's receiving.
Edit#1: I also think people hate her because Nami hates her
Edit #2: Nami started hating her because of Nami's own feelings for MC. Nami's in-love with him but the tabboo of it all kept her from doing/saying anything about it. Meanwhile, Summer came, saw something she liked, and just took it. Summer probably didn't even
know that Nami had a crush on MC. Nami
chose to distance herself from them after they started dating. They had no problem hanging out with Elsa when they were dating, so... what? In Nami's eyes, Summer broke the girl code. In Summer's eyes, there was no girl code to be broken. I'll stop here because this is a
whole other topic... but the thing that killed their friendship was Nami's resentment. What's messed up is that she's still resentful
to this day despite the fact that Summer could be
dead for all she knows.