BvS, which I liked well enough, tried to do too much in 2.5 hours. You can tell the movie was largely butchered from trying to reduce the run time. I think the execs at Warner Bros are probably the biggest ones to blame. Synder cannot be the only scapegoat here.
MOS didn't have the box office WB were looking for, so they inserted the moneymaker that is Batman. They also decided to world build on top of all that. You cannot have two protagonists, a new villain, a side character that is Wonder Woman, and future setups for other movies in one fell swoop. Iron Man 2 didn't work because it was too busy setting up The Avengers. BvS messed up on slightly larger scale, because it was trying to bite off even more than IM2.
Even so, BvS is not a complete failure. I certainly look forward to Ben Affleck's Batman in future movies. He was almost universally praised in the role, and Gal Gadot's WW was liked to a somewhat lesser extent. Suicide Squad, I hope, will be a step in the right direction. All the other upcoming films are such a huge question mark, especially Justice League. I think people are still willing to give things a chance, but WB/DC are on a short leash right now. Any more screw ups will not bode well.