It's not that I have no faith in the project. I'd be interested to see how it goes, but then I remember the last time a major DC superhero ensemble piece was planned, and what a clusterfuck that turned out to be. A fairly good cast (Adam Brody, Armie Hammer, Common, etc.) being shoehorned in with no prior solo films, a model being hired as a major character (Wonder Woman), etc.
And no, this isn't like Ocean's Eleven, where the majority of the team was limited to background or minor roles. You have an all-star cast that's going to be competing for face time. Doesn't make it a bad thing, but I still worry about whether some characters are going to get a short shift.