Don't get me wrong Gaspar. I want this movie to do well. I'm a comic book fan, I love Marvel a little more but I also love DC.
The challenge is that WB/DC needs to get fans AND casual movie-goers to CARE about their characters in order to help drive ticket sales. Obviously, Superman and Batman get much love and anything with "Batman" in the name basically guarantees interest and success. But it's those OTHER heroes that DC needs to get movie-goers to relate to. Characters like Cyborg and The Flash, and ESPECIALLY Wonder Woman. It's very easy to compare them all to Marvel but why not? A prime example is Black Widow. They've done so well with building her over the movies she's been in that I've heard from my casual movie-going buddies saying "When is Black Widow getting her own movie?". They CARE and are INVESTED in the character enough that they want to see more of her. That is why there is a lot of pressure on Gal Gadot to perform. She will either make or break Wonder Woman.
But just throwing in characters here and there isn't going to make the audience "care".
And "Green Lantern" SHATTERED WB's confidence. Its self-esteem is at an all-time low after that which is why it has (in my opinion) had to resort to bringing in the BIG GUN, Batman, into the Man of Steel 2. And it makes for concern whether they'll try to branch outside of their "comfort zone bubble" of Superman and Batman. These characters (Cyborg, Aquaman, Green Lantern 2.0, and Wonder Woman) might NOT get the opportunity to get their own flicks because WB just doesn't have the confidence in them or isn't willing to "smartly" develop them in the Justice League/Batman/Superman movies.