I beleive the Justice league movie can succeed either way with or without lead-up movies but I do acknowledge it being harder with no lead-ins due to it having a few negative qualities.
NEGATIVES OF NO LEADUP-NO 1:
With the exception of Batman and Supes non of them have Public draw power. People always argue that Flash,WW,Gl are more iconic than the avengers characters. Yet I dare you to ask a kid what what Flashs secret identiy is. Youll get no answer.Ask them what Ironmans secret identity is and theyll give it to you without blinking.The movies have moved heroes like Iron man from "simply recongnizble" to "Public drawing heroes".Flash,WW and to a smaller extent GL are still "simply recongnizable"
Basically it goes down like this
The appeal of seeing JL movie without solos-Bats and supes
The appeal of seeing JL movie with solos-Bats,supes,flash,GL,WW.
look at both and you can see why the solo movie approach is superior-It has more appeal. A JL movie without solos will ineveitably be less of an event than one with solos. So a Jl movie without solos will be less successful than one with solos--THAT DOESN'T MEAN IT WILL FAIL.It just means the JL movie wasn't as successful as it cld have been
NEGATIVES OF NO LEADUP-NO 2:
The other problem the spinoff approach has is establsihing the various mythologies of each hero in the same universe with one go.
For example Establishing Wonder woman mythos(fantasy) and Green lantern mythos(sci fi) in the same universe and having them interact normally.
It also has to constantly explain aspects on the mythos as they are introduced in the Jl movie explanations that take up screentime and detract from main plot.Explanations that wld have been covered in solo movies.
NEGATIVES OF NO LEADUP-NO 3:
Jl movie following the spinoff approach has to Get all characterisations right in one go and seeing as they cant use solo leadins as template like the avengers did,this will be more difficult.
Getting the characterisations right is not just for the sake of the movie but for the spinofs.Fact is The Jl director is essentially in one go setting up the groundwork for the solo movie spinoffs and theres a good possibility of making a mistake since he is focusing on so many characters.Its not like Marvels appproach where they systematically built the groundwork for each solo movie in its own movie thus minimizing errors.Whoever is writing the script for a JL movie needs to essntially have a grand plan for the entire solo movie spinoffs
NEGATIVES OF NO LEADUP-NO 4:
They have the risk of being seen as a superhero team(Fantastic Four,Xmen) instead of being seen as a superhero team up(Avengers) without Solos.
Now dont get me wrong,I think a JL movie can very much succeed without solos after all it has Bats and Supes. But there is no doubt in my mind it will have succeeded a whole lot more with solo movies leading up to it,and a lot easier.
I do need to piont out though that nearly all the negatives of the no-leadup approach can be eliminated if Extraodinary storywriting skills are applied to the movie.Im talking LOTR type writing skills
Anyways There are 3 main advantages to the no lead-ins approach
POSITIVES OF NO LEADUP-NO 1
is that we get a Jl movie earlier than we would with Solos(its this main plus that blinds people to all other disadvatnages of this approach)so its a big plus for fans.This advantage is also great for WB as it allows them to release a Jl movie as fast as possible-whilst the superhero crze is still going strong instead of risking releasing it in a time when the crze might have died.
POSITIVES OF NO LEADUP-NO 2
The no leadins approach gives Dc a chance to ctach up with Marvels movie within a short amount of time
POSITIVES OF NO LEADUP-NO 3
is that Spinoff movies are less likely to fail financially.This advantage benefits the studios not the fans though.
It simply means that WB will be in less of a financial risk when releasing the solo movies.
I personally dont care for this though -kinda seems like that they dont beleive in their characters hence why they feel the need to have them sponge off Batman and Superman s popularity to simply have a chance at the big screen.But I cant deny its a good business decision
So do I think WB is making the right decison to release a JL movie without leadups?My answer is Yes.The reason is WB/DC doesnt have the luxury of solo leadups as theyve fallen behind marvel due to their stupidity and now are just awakening to it.They really have no choice especially since they need tentpoles.That being said nearly all of the negatives of this No leadup approch can be nullified with Awesome storywriting so its not bad..
I need to piont out something at this piont.Quite frankly whether or not the JL movie has leadins, It will face Avengers Copycat accusations-they are inevitable.If they go with leadins,theyll be said to ripping off marvels approach,if they go without it they will said to be trying to rip off marvel without putting in the hard work marvel did.Its a no win situation,The best Dc can do is just to try their best to make JL as unique and as awesome as possible and all those accustaions will be forgotten when the movie is released