It's also worth noting that the percentage of drop isn't necessarily a box office killer, under the right circumstances. If you open with sufficiently large numbers, you can offset the drop and assume that your marketing worked really well. In other words, you maximized the value of your marketing by turning out a huge number of people opening weekend. Everything after that is gravy, assuming you end up with a more normal 50% drop week-to-week after the first week. So, if you figure a film gets a month-long run, and it opens at $300M, then drops 70% by its 2nd week to "only" earn $90M, 50% drops for the next two weeks means you still have a damn successful film (depending on the budget, of course).
All that said, we may be seeing a "narrative" form in the media that follows films: namely that DC films are -- or at least have been -- a mess, and the ones that are currently in the can show no signs of changing that trajectory. Audiences...you know, like 'em, because they're big action comic book films...but they don't LOVE them the way they do Marvel films. And make no mistake, that's what DC/WB wants.
Warner Brothers' shareholders want performance like Marvel. "Give us Marvel-like successes." That's the order. And thus far, that order has not been fulfilled. Even if these films are successful by financial standards, they are not successful enough.
I think a lot of this stuff is why Geoff Johns has been tapped to take over the franchise. I don't know if folks here have read his work, but my view of him is that, on the whole, he "gets" the DC characters and what makes them tick. His run on Green Lantern was terrific and he parlayed that into Blackest Night, which was also terrific. Everything built organically, and I felt like he understood the characters he was writing about. And while there was certainly death and destruction during these periods, there wasn't an omnipresent sense of gloom and doom and I'm-flexing-my-grim-and-gritty-muscles-SO-HARD. Not everything was infused with Frank-Miller-Batman DNA.
Putting him in charge of the overall creative direction of the DC properties is, in my opinion, an excellent choice. DC has such rich material, especially for purposes of creating truly uplifting, optimistic stories. There is simply no need to leave their entire franchise mired in grimdark nonsense.
And the truth is, for all of the handwringing and wailing and gnashing of teeth about the future of the franchise...DC is gonna be fine. For God's sake this is SUPERMAN we're talking about. And BATMAN. Two of the most durable properties ever created. I mean, if Superman IV: The Quest for Peace or Batman & Robin couldn't drive a stake through the heart of DC's film franchises...they're pretty much invulnerable. And remember, even when he's hit with kryptonite, Superman always ends up bouncing back. So, sure, the box office for this version of DC's films has been disappointing. But that doesn't mean we'll never see DC films again after this.