lol
WTF are you talking about? John has always been treating Jamie like a sister, she's been friendzoned even though everyone who know both of them see what's happening. And not only that, judging by "it's just a little more sharing than I'm used from you" or "not that you'd ever allow anyone to have an intimate conversation with you" that she says to John, shows us that he keeps her at a distance even though they've known each other for years and the most intimate moment they have after all this time isn't even a kiss (while meanwhile he can have sex with everyone else and here it's not even 1st base, it's 0 base - a hug). If anyone should leave the story it's John, typical boring and unrealistic hero (super fast, faster than Bolt at the 40 yard distance, his skin is knife proof, can fight 8 people at once without any training and win, is the star prosecutor, etc.).
Anyway, Jamie has always had his best interest in her heart, starting from telling him to not work so much or always giving him good advice and wasting her own time to help him do his work (you're saying something opposite, that John had supported her but we don't really see that besides him praising Jamie during their meeting at the bar). She also notices small details when it comes to him, e.g. that he moved his mom's picture or that he's been working all night or what eye color his mom had (meanwhile AFAWK John couldn't tell that something was bothering Jamie during their trip to her parents, even after she slipped up and told that she will miss west coast weather). We also know her inner thoughts and she ALWAYS made John's interest her priority even if it went against HER interest, e.g. when she convinced Luis to allow John to work on the case knowing perfectly well that it would bring him and his ex-girlfriend closer together ("I'm going to regret this but this is what he wants").
And seriously, if John can't take a hint after Jamie saying stuff like "Oh, I'd take you" and you're still calling Jamie self-entitled/horrible then I really don't know what to say. Not to mention that with her credentials and connections she could have gotten job anywhere (and much better than county prosecutor) but she chose to be close to John and he's too stupid to realise that (at least he realised that he was cockblocked by her at the bar but he still couldn't draw the right conclusion from that and explained it as her being drunk and even when Sean explained to him what was happening and how it really looked like from the side he still didn't believe).
Also, it's funny how one sided you are. John is basically a no-life, workaholic with daddy issues so WTF should Jamie abandon her dreams and career when it's John who has nothing to lose (he could be a prosecutor where she's going and his life wouldn't change much)? Although I'm pretty sure that Jamie would drop everything for him if he would tell her he loves her (and not like a sister, then again maybe like a sister if we take into account latest plot-twist). And let's not forget that Jamie explicitly said to John that she wants to be a federal judge and she literally said to him that "Getting what I want might mean leaving Santa Valeria County". She's been up-front about it this whole time.
Last but not least, she did tell him about her plans when the time was right (she didn't want to ruin their trip so she waited until they were going back) and stopped John from kissing her even though she wanted it more than anything. But she wanted to be honest with him and didn't want to hurt him in the process or use him. Her crying shows how hard this decision must have been for her. And as Trevor said - this is unrequited love, even when we're choosing dialogue options focused on Jamie we're far away from romantic love at this point. Jamie telling him about her decision will be a turning point and we as players will decide whether Jamie will stay in game as one of the LIs or not. After all you don't think that the author would focus all this time on Jamie just for her to fly away, do you? Unless we wouldn't care about her of course, then her decision will be the only course of action she should take.
What is most ironic though is that the only self-centered person here is you. Not John, not Jamie but you. You have a notion that Jamie must suck John's dick because he's the only important person here. Jamie's wants, feelings or dreams are irrelevant and any course of action where John isn't worshipped makes her disgusting. WTF man?
Seriously, how can you say that family is rotten or disgusting when they've been nothing but good to him. They've financed a nobody, they let a bum-child spend time with their children and Jamie and Trevor have supported him for years without expecting nothing from him. And now that he's an adult we're supposed to think that John is so fragile that he would be hurt if Jamie (who up to this point was no more than a friend to him) went after her dream which he knew about and which he himself said that she should do?
And sorry but Trevor does make a good point - it's 2025 and you can easily keep in touch with one another and with fast travel you could fly from west coast to east coast easily. As things stand now not much would change if Jamie wasn't there unless you're suggesting that she needs to be available 24/7, holidays included whenever John will have a fever or want to cry on Jamie's shoulder while at the same time he would treat her like a friend at best.
I want you to be honest and answer this: what conclusion would you draw if your loved one would always keep you at a distance even when you couldn't be more obvious? As Jamie said:
"I still have feelings for him, but I'm starting to think that maybe it's time for me to grow up and move on. If that's what needs to happen I'll accept it. But he'll still be an important part of my life. I'll always care about him as a friend."
But the most crucial part where we can clearly see what Jamie wants is this one:
Seo Jun: And if he comes to you tomorrow and professes his love?
Jamie: Then we will immediately engage in 72 straight hours of raucous lovemaking.
tl;dr
You're wrong on every possible level.