I have a really hard time taking these criticisms seriously. 
@bozinga - I don't understand the whole "Joel suddenly became stupid" argument. Abby liked and was thankful to Joel. They weren't luring him into a trap- It's nothing like the first game with the scavenger in the street. That scavenger was a "bait". Conversely, Abby wasn't baiting Joel. she actually was about to die. So to Joel, there wouldn't be any reason for suspicion. He just saved her life. I don't see 'this person might turn around and kill me' to be a logical forethought. Perhaps he should have been more cautious, but consider this: Had joel been any other person, he wouldn't have been killed. Logically, the only real argument you can make is that it was stupid to say his own name. However, we've seen in almost any movie or literature on survival, going from difficult conditions to comfortable (living in a town that grew to hundreds within 4 years and are all friends) tends to make people let their guard down. You're entitled to think that Joel's stupidity was just a poorly written plot device, but it's definitely up for debate and you're point is not as singularly convincing as you seem to think. 

Furthermore, the whole setup-confrontation-conclusion argument you brought up hinges on you accurately identifying the story elements. You say that the story is all backwards and mixed up and doesn't make sense. But there are hundreds, if not thousands of revenge stories that are written with a similar type of setup.
-In Kill Bill, you have no idea who Bill is and why he killed the bride or why she wants revenge.
-In The Gladiator, Maximus is an actual war hero and is given heirship to Rome by the terminally ill emperor whose son then kills Maximus' whole family in a bid to steal the throne.
-In Hanna, you have no idea why the government comes and tries to kill her father. all you know is hanna goes bonkers and starts killing everyone. 
-In OldBoy, the story starts of with the lead being kidnapped and tortured and we have no idea why until things play out and you find out the main dude is actually a huge PoS.
-Do I even need to bring up Darth Vader in star Wars being Luke's father? Does anyone really need to see Anakin's life story before I can understand why Vader is so insistent on capturing Luke? 

You say that we need to see Abby's story before we see her kill Joel, but do we really? We PLAYED the first game. We know how bad Joel is. For all I care, the first game IS Abby's exposition. 

Joel is a villain- Despite bonding with him, or liking him, or even agreeing with his actions. Joel is a villain.
When Ellie asks how Joel knew about the trap he responds, "I've been on both sides". He's trapped and killed innocent people EVEN BEFORE he ever meets Ellie.  Regardless of making ends meet or surviving, we also see his moral failures towards the end, wherein Joel offers just go back home and Ellie replies,
"if I don't go through with this, then everything we've done.. everyone we've lost...it's all for nothing"
Joel then kills the entire hospital, the resistance, Marlene, and condemns humanity. Joel betrays and dishonors everyone you met in the game, all bc he wants to keep Ellie to himself.

TLOU is great game specifically due to how the narrative induces compassion for Joel's journey.... If you honestly need more exposition to understand Abby's motives at that part of the game, then I'm afraid to say that it's pretty obvious why. You didn't understand the last of us. 

Playing through it myself, I was also surprised that Abby was out for revenge. I wrongly assumed that since she was kind of normal and I had been playing as her, she would be a good guy. What's more interesting is that even now, I can't think of a reason to say Abby was wrong to kill Joel. AFAIK, Abby's story begins 4 years earlier when Joel kills her father. AFAIK, Abby could actually be the hero of her own story, climaxing with her killing the target of her vengeance. If you think about it, Ellie's journey in TLOU2 is Abby's exposition. Abby is just Ellie from the future, if you understand my meaning. The difference being that Abby didn't spare her target and Ellie does. 

The way you described how the story should have been written, we should have played out an entire story of Abby's revenge and then played out Ellie's revenge. Honestly, I can't think of anything more tedious or boring than having to play out the same plot twice.

Something like that would have been better, yes. I actually expected Joel to die, but not like this. The problem is that the story from Abby's side is not set up properly and her as a character isn't built up with sufficient time in order for us to care for her even one bit. She just shows up like this roid raged monster that brutalizes Joel and we're supposed to appreciate "her side of the story".

Just to add to bozinga 

Joel was morally corrupt in the first game and ellie was his chance of regaining what was lost.. yes in greater scheme of things that's selfish and wrong but that was the cruz of the last of us.. which took almost 10hrs to show why you shouldn't feel bad about joels decision.

If in first game Joel's action was handled in similar way as Abby's.. Starting of killing the doctors and ruining every chance society to rebuild itself.. we wouldnt have considered last of US as masterpiece.

The problem with TloU2 is neil druckmann and Shanon woodward got complacent and probably thought hey lets break the rule of story telling, which is 3 act structure.. setup, Confrontation and conclusion, in that order, but instead we got 

Confrontation - Joels death was the conflict but falls flat due to no setup of why he deserved to die, rest alone in that manner..

Setup- Abby was directly thrown into confrontation, (no character setup or situation setup)

Conclusion - this entire thing got lost when writer didn't know who's story deserved conclusion.. what players should feel towards Abby.

it would have been a much better story if we started playing as Abby recruiting the team on quest to finding joel. and show why she hated joel so much and it was not just because of her father but there were many things joel and we as a player did in the first game that would deconstruct joel in our mind.. and then setup a confrontation with abby, we as a player fighting as joel along with tommy to give player the sense that joels death was our doing. and then from that we would have had ellie's journey on revenge and the conclusion which we got would have made much more sense..

P.S Scars was pointless to the story..

You are merely projecting your logic into the matter but don't really have anything concrete to back that up. It's not that Joel does cannot trust people, but it is clear he does not let his guard down that easily. Case in point, when Joel meets Henry and Sam. It took them a while before he completely trusted them. For Abby and her friends, it was almost instaneous. Why he did so is everyone's guess.

However, I kinda see what they may have wanted to portray with this current Joel. Joel has or is trying to move on. His house was filled with things that he likes. He seems to be respected by the people in the town judging by all the flowers people left at his home. Seems like he may be trying be a better person. Not just to Ellie but to everyone else. But without having anything solid to bridge us from TLOU1 Joel and the current Joel, it comes out severly lacking in context and just forces people to formulate theories. I enjoy a story that has a continuous flow. These flash backs served nothing but just force context to conveniently support the events that was happening or is about to happen. It's also one of the things that hurts the pacing so bad.

If you are having a hard time taking the crticisms pertaining to Joel's death seriously, a lot of people are way ahead of you as people like me can't take anything in this game's story seriously with how bad it is.

I am glad that I was not the only one here who loved the story. I think ND did the right thing by not re-telling yet another Joel & Ellie story, instead they focused on Ellie and a brand new character.

I kind of hope this is the last game in the series, though that's how I felt about the first game as well, and look how great this one turned out. I know it's not a popular opinion right now, but I think that Druckman managed to grow into one of the finest storytellers in the gaming industry

Edit:

It's kind of off-putting for not being able to express my love for a game without having some vitriol thrown into my face. I didn't talk down on anyone for disliking the game, nor would I do it, so in the very least if you don't have anything even remotely constructive to say I would appreciate if you would not respond to my posts in this thread anymore.