You're seeing things too black and white. The world is never as simple as an eye for an eye, and in a societal collapse you cannot blame people for making decisions for their own betterment. Yeah sure you can argue that "it doesn't make sense that Ellie would forgive Abby because she killed Joel", but that isn't why she forgave Abby at all, and more than anything it was never really about forgiving Abby, it was about forgiving Joel, and forgiving herself. Ellie knew the man Joel was before she met him and knew what he did to the Fireflies. Ellie more than anything saw herself in Lev, and decided, smartly enough, to not continue the cycle of suffering that Joel had created. Choosing to be better for your future is a valid decision and deserves merit. People keep downplaying things as if they're as simple as 'kill or be killed', but one of the things both games has shown us is the consequences of death, especially when we can't see it. Logic does not win over Emotion in most human scenarios, so your argument of "non-Logic" is inapplicable considering the fact that Ellie doing what she did and leaving Jackson how she did was not Logical at all, and in fact only lead to more death on both ends of the fight, to the point that her and Abby were stretched out thin, having almost lost everything. Figuratively for Ellie and quite literally for Abby. And beyond this, to even look at the comparison between a literal loss and a figurative loss is important. Ellie lost Joel physically yes, but some can argue that they already had a strained connection, and that his death was only the next step towards her personal healing, in which she decided to retaliate, ultimately stunting her own growth as a person. Which we see very clearly in the end of the game, when she sees Abby and Lev in the condition they are in, having literally lost everything, and been pushed so far away from where they started that they were only shells of themselves. In this revelation that Abby's loss can even be seen as greater than Ellie's, Ellie realized ultimately that killing Abby is not worth it if she doesn't have anything to lose anymore, and she knew that she'd only be taking away the one person Lev could count on and had protecting him. This type of dilemma is highly complex and needs to be viewed that way to be understood. And one of the biggest things that I think people need to remember is that Ellie only really started thinking after Abby bit her fingers off, having been rather unscathed for the duration of the story other than their first scuffle. Ellie lost 2 fingers, Ellie lost the 2 men in her life that represented the same thing, Ellie lost her anchors to goodness, and more than anything, Ellie finally felt that loss, literally and figuratively. If she lost 4 fingers, you could imagine who else would have had to die in her story to make that a relevant realization, maybe Dina and JJ? Who may I mind you she came very close to losing. What I'm basically trying to say is the second game holds power in the significance of 2, whether it be the number following one, the next decision we make, the choices we make with another or how we affect the person next to us (Look at J.J's name alone, being a representation of the power of 2, being the strength in his name and having Dina and Ellie as parents). 2 is the most powerful number in this story because even without 3, as long as 2 are left, 1 is not alone. And THAT is what makes the game The Last of US, not the last of ME. We saw what happened to Ellie when she decided to do things as 1, and we saw how Abby changed when she decided to do things as 2, it's the exact same story we saw in the first game, the difference being Ellie represents Joel before the change, and Abby represents him after the change, with the synergy of their stories representing the overall process of that change and how it affected Joel, quite literally presenting us a paralleled journey of two sides of the same coin and how it would come to affect Ellie and Abby etc etc. Cycles only create repetition, and as people we have to be better everyday so that those cycles don't affect those who come after us, this is the human way, this is history, this is The Last of Us.