Snyder, WB executives being retarded, no proper planning, and so on.
A DC cinematic universe should be easy as fuck to make, practically write itself, and print gold. You really do have to try to fuck that up. All you'd need to do is follow Marvel's BASIC formula of giving the biggest heroes their own solo movies that also (for the most part) cover different genres, building up to the big team-up movie in Justice League. You could deviate from the Marvel formula in some ways, like cutting down on all the humor a bit, and not killing off every fucking bad guy at the end of every movie, which would be for the best since DC in general has better villains than Marvel.
There. That's all they really needed to do. >>99073603
I actually don't think there's anything wrong with the IDEA of giving us a more experienced Batman. The problem is that they made him way too old and then made BvS a rough adaptation of TDKR when it didn't really call for it.