Phobia: an extreme or irrational fear of or aversion to something
Some fans of The Last of Us seem to have a phobia of The Last of Us 2 (Thelastofustwoaphobia). People are afraid that a Last Of Us sequel, or at least one continuing Joel and Ellie's story would ruin the impact of the first one. you see a bunch of articles about how "we don't need a Last Of Us 2" and "if The Last Of Us 2 has Joel and Ellie, their relationship would only sour". well I'm hear to tell you that this fear is an irrational one. The Last Of Us fans should be excited for The Last Of Us 2, not afraid of it.
6.The Last Of Us will still exist
Even if The Last Of Us 2 is a terrible game, the first game would still exist and you can always go back to it, and get the same feelings you always do. For example, one of my all time favorite movies is American Psycho starring Christian Bale, but it's sequel American Psycho 2, is one of the worst movies I have ever seen! (you seriously expect me to believe a psychotic version of Batman is going to be defeated by a 9 year old Mila Kunis?) but even though American Psycho 2 is just awful, it doesn't make me like the first movie any less, I just pretend the second one doesn't exist.
5.Joel and Ellie have a lot of backstory, and untapped potential
A lot happened to Joel in the 20 years since the start of the apocalypse, and those 20 years are ripe with the possibility to tell a great story. That time period has a lot of questions that could be explored; How did Joel meet Tess? Why did Tommy leave the fireflies? Why did Tommy and Joel fight? And, HOW THE HECK DID ELLIE GET THAT SCAR?!?!
Joel and Ellie's story also has a lot of potential moving forward. Their initial journey may be over, and that one story about Joel and Ellie trying to find the cure may be over, but whose to say they can't tell another story about these two. Maybe Ellie could become a smuggler, like Joel, or maybe Ellie gets lost somehow. The game could revolve around Ellie trying to get back home. Or the hole game could just take place in Tommy's village, focusing on how Ellie copes with what she's been through in the first game.
The Last Of Us is a heavily story based game, that doesn't need to be some glorious epic showing off a vast post apocalyptic world. It can, and should, just be a simple and focused story further exploring it's characters. it can be in just one place, it doesn't need to show us every inch of it's world, it just needs to have an engaging story, with a likable character we can all root for (like Ellie).
4.You need to take risks to achieve greatness
Yeah having The Last Of Us 2 bring in new characters is an easy way not to "ruin" the first game. However if the sequel tells an all new story with new characters, while it may not ruin the first game, it would likely not be as good as the first game. It would feel more like they're just making another zombie/ infected type of game, because they need a sequel. You may say they shouldn't touch the original, because they could ruin it, but I think they should take that chance! Naughty Dog is a company with some talented writers, that have a lot of respect for the characters they create. Joel and Ellie are great characters, and Naughty Dog should not be afraid to show us more about them, they should take that risk, because I know they can still tell many great stories with these two, and I know they will treat these characters with the respect that they deserve. Besides, getting rid of a character is something you do when you don't like the character, not when you do. If you have a really good character like Joel or Ellie, you should keep them, especially if your as talented as Naughty Dog. They should make a sequel, not because it is easy, but because it is hard.
3.Games are different than movies
A big reason a lot of people fear a Last Of Us 2, is that they are looking at it as a movie. Yes The Last Of Us is a very cinematic game, and is very much like a movie, but it's not a movie, it's a video game. While in the world of movies, sequels are almost always bad, but it's the opposite with video games. In the world of video games, it's actually common place for the sequel to be even better than the original. Take the Arkham series, Assassin's Creed, many of the Mario games, the Metal Gear Solid series, and of course the Uncharted series. Like movies, games are a medium to tell great stories, but were games differ from movies, is that they are interactive. In a game you are in control of the story, that's why it's much easier to make a sequel to a video game than a movie. In a game, it's easier to continue a characters story because the player has control of the character, and can have them act how they think the character would. Naughty Dog has shown that they are starting to put more choice into their games. Uncharted 4 is said to have areas were you don't need to kill everybody to move on (though you certainly can) and the Last Of Us DLC Left Behind, had moments were you could choose different Dialog, and were you can choose some of the choices Ellie makes. So it's likely that if we get a Last Of Us 2, we would be given a lot more choice in how the story plays out, we may even be able to choose if Ellie can forgive Joel for lying to her, and I think that's what they should do, that way we would be able to see our version of the story play out, and the character won't be ruined that way.
2.The Last Of Us has an opportunity to tell a great story
If Naughty Dog decides to make a spin off instead of a sequel, it could be a good game, but it won't be a great game. I have read an article once, saying that "The Last Of Us shouldn't be a franchise that chronicles the lives of Joel and Ellie". While I respect anyone's opinion (or at least try to) I have to respectfully disagree with this. We see many post apocalyptic style games switch the main characters, to show us more of it's world, but what makes The Last Of Us so special, is that it's world is meant to be in the background. I think if The Last Of Us franchise, would let us see Ellie growing up in this world, we would get more of an attachment to this game, and it would be more meaningful when the series comes to an end. If The Last Of Us became an episodic series, with each game telling a new story, with different characters, when we get to the final entry, it won't feel like it's the final chapter, rather it would just feel like another Last Of Us game, and the series would just disappear into obscurity, lacking that dramatic conclusion it could have had. However if The last Of Us fallows Ellie's life, when we get to the last entry, it would truly feel like it's the final chapter, because it would be the last chapter of Ellie's story. (weather that means she dies, we'll leave that up to the developer). To me, watching Ellie grow up in this world, is a far more meaningful story than any of the lore of The Last Of Us.
1.If you don't wan't a sequel, don't buy it when it comes out
In the end of the day, it all boils down to this. No one is forcing you to buy anything! If you still, really do not want a sequel to this game, and if you really think that continuing Joel and Ellie's story would "ruin the impact of the first game" (which is totally ridiculous) then just don't by the sequel, it's as simple as that. No one is making you buy anything, if you don't want to see how a characters story arc continues, just ignore any sequels continuing their story.