Let me preface this by saying that I believe that Geoff Johns is an amazing writer who has made numerous contributions to the comic book, television, and film industry over the last 10 years.
He really stands out from the rest of the comic book writing crowd for his ability to flush out the psychologies of villains (Sinestro, Black Manta, Parasite, etc.), he knows how to use side characters to enrich the story and to add interesting bits of drama (as seen in Green Lantern, Aquaman, and Cyborg), and he knows how to make big reveals feel organic. Until the reboot, his only problems as a writer were that his single could feel a little decompressed from time to time and his main characters could feel a little bit like Mary Sue's from time to time--but it was no big deal because those stories revolved around super heroes.
I was extraordinarily excited about his Justice League run with Jim Lee when it was announced, but I've only enjoyed 2 of the 11 issues that have been released so far (Issues 1 and 9). So what's wrong with Johns's run?
1) The Characters Are Too One Note
Every team book is bound to have types. As a writer, you're working with 22 pages a month, so you often have to boil down your characters to their essential personality traits to make each character interesting. There is nothing wrong with that. It works well for the Ninja Turtles, the Young Justice cartoon, and too many other plays, shows, films, and video games to actually list. The problem is when the characters a TOO one note. How many times do we have to put up with the same Aquaman jokes over and over and over again. It was funny the first time in Aquaman's New52 solo title, but now when I see it again I just want to tear up the issue--it's not funny anymore and we get the joke. It's time to move on because it's just starting to feel like lazy writing to take up a few panels.
Green Lantern is supposed to fit the joker role on the team similar to Iceman, Spider-Man, Human Torch, and Iron Man, but Green Lantern's jokes have no real heart like those other characters. The joker is supposed to feel fun and playful--and his team mates should like his jokes occasionally. The reader and the other characters should laugh WITH the joker not AT him. That's not the case with Green Lantern in the book. He's just douchey. He's a clown. I forgave it during the first arc because he was still a new hero to the scene, but he still acts very rudely 5 years later. No one would actually want to be friends with this guy in real life, so why does the Justice League put up with him? He hits on everything that moves--sloppily I might add. He tries to pick up his friend's girlfriends (see issue 10). He put's people at risk to punk Batman (see issue 7). He's a jerk in a non-entertaining. way (see issue 1-11). I could put up with this if he were A) actually entertaining or B) is it happened rarely. But it's not entertaining, and Hal acts like a jerk every issue (except issue 9). Why is the writer who made Hal popular again writing him as a one note douchebag in an attempt to make him the funny guy? It's such a contrast from the Green Lantern ongoing and from his previous work with the character.
Wonder Woman is supposed to be this team's Wolverine, but she doesn't show the kind of heart needed to balance it out. And we don't need to reference the fact that Barry Allen is a cop who loves the law in every issue. And we know that Batman has no powers. LET'S MOVE ON.
Furthermore, we see the same team ups over and over. Batman and Superman always hang out. Flash and Green Lantern always hang out. Let's change it up. How about Superman and Aquaman? Cyborg and Flash? etc.?
Finally, why does the team constantly fight? They don't seem like they should really be friends because they can't stand each other. Why don't they get along some of the time? The Avengers and X-Men strike a good balance between team conflicts and unity. This team does not.
2) It's Too Decompressed
I understand taking your time to write a good story, but very little development actually happens in each issue. Some times there's hardly any dialog on a page no matter what the panel count is. While this is not a big deal in terms of buying for trades, it does make buying single issues feel like a waste. Now some writers think that they should solely focus on single issues which rushes the story too much (See the Manapul and Buccellato Flash) and other writers like Johns and Bendis write fr trade and leave single issues feeling worthless. There can be a balance between the two as seen in Snyder's Batman and Johns' Aquaman.
3) It Has Too Many Main Characters and It's Trying To Make Everyone Happy
Everyone has a favorite member of the Justice League who they want to see take center stage. Okay that's fine. Problems arise when you have too many of those characters trying to take a main character slot. Any writer or director will tell you that it is EXTREMELY difficult to coordinate fights with more than 5 characters. It's also hard to write worthwhile dialogue for more than 6 characters. I care more about dialogue and character development than fights, so I think that at most it's okay to have 6 main characters, but you can have hundreds of supporting characters is you'd like. Justice League breaks that rule and has 7 main characters. I know that the League traditionally has 7 heroes, but that doesn't mean that that is a good thing. At best a character just isn't given much to say or do (see Colossus during Mark Millar's fantastic Ultimate X-Men run, see Starfile during Geoff Johns's Teen Titans run, etc.), while the other characters take up the limelight. This can be fixed by splitting the characters up into smaller groups, but all 7 Leaguers are together most of the time which means that characters like Superman, Aquaman, and Wonder Woman say little while everything Cyborg says is exposition. Even the Avengers film and Joss Whedon's X-Men only had up to 6 heroes in the room at once.
The best way to fix this is by making some of the characters (up to 6) main characters while the rest are supporting characters. Yes this will piss people off if you advertise their favorite character on the cover, so just don't advertise their favorite character on the cover. By trying to use all 7 as main characters you're just annoying people who aren't Batman, Green Lantern, or Flash fans.
Some people may say that it's okay to have a zillion main characters like on Young Justice or JLU. But comics don't run on a weekly format like those shows which can neglect a character for a week or two. You can't neglect a main character for a month or months at a time.
Finally, not every character needs to be in the book every month. There are solo titles for that. Don't shove characters in to make people happy. It's about the quality of the time with the character not to quantity. It irks me when Wonder Woman and Aquaman are in the book only to get two lines of dialogue. Just leave them out of the issue that month, then have an Aquaman and Wonder Woman centric book the next month.
4) No Sense of Danger and No Build Up
Okay, we've seen heroes fight block buster style alien invasions a zillion times. Do we really need to see that again? Do the heroes need to win every time? Take a note from the Young Justice cartoon. Have the bad guys actually be cunning and sneaky. It makes the stories less predictable. Also when the bad guys do attack, don't just have them blow up a bunch of cars. If the bad guy is evil he'll do things like kill innocents and his own followers. Take some notes from Watchmen (wipe out of New York) and Ultimate Comics Ultimates (wipe out of DC).
5) It Feels Targeted To Parents Who Don't Read Comic Books
The book feels so bland and inoffensive so as to make parents feel comfortable buying it for their kids at Barnes and Noble when the movie eventually comes out. It's too koscher. Bad things can happen in a book and it will sell (see Watchmen or Batman: Year One). And just because the book is clean doesn't mean that kids will like it. My little brother (10) thinks that the book is for little kids, but he's a big fan of the darker Young Justice. You can be appropriate for children and still be dark and mature (see Dr. Seuss's The Lorax and Bruce Timm's Batman the Animated Series).
What ever happened to stories like Justice, New Frontier, Tower of Babel, etc.?
6) Predictable Reveals
Johns' is supposed to be good at surprises, so why is there nothing surprising in Justice League?
7) Geoff Johns Can Do Better
Why is Aquaman a FAR better team book than Justice League? It makes no sense. There's too much wasted potential in this book.
Can we get some ages for the characters and a timeline please? I get this is supposed to be timeless, but there are just too many holes in this universe.
What is Great About Geoff Johns' Run?
Cyborg is more interesting than he's ever been, so now I want a Cyborg solo book. The characters have personalities instead of being silver age carbon copies of one another. And I like the roster. David Graves seems like he could be a cool villain. That's about it.