The worst thing to happen to DC Comics films will be the "cinematic universe" concept, both broadly speaking and in any move DC makes to ape the house style of Marvel's films.
The only real weakness in Batman v Superman is the comically shoehorned in tie-in bits for Justice League. These scenes speak to the friction in these films between entertainment, art, and advertisement. JL runs the risk of becoming nothing more than an Avengers-esque piece of marketing for its own sequels and spinoffs, and in the released scenes strikes the same brutally unfunny "humorous" and "quippy" tone as Whedon's films.