Well, if it haves all that "in your face" chosen one mumbo jumbo, then BvS is likely going to be flashy action with no brains. As of now, I have low expectations for BvS, while at the same time I'm on board the hype train for Civil war.
Also probably because we know that Civil War, in general, being part of the MCU, was planned long ago. Marvel really had a very ambitious idea starting with Iron Man and have a pretty clear map made to follow all the way to Infinity War. Even when things change, Marvel has shown to be able to adapt and adjust, like when Edward Norton left and leaving no one to be Bruce Banner/Hulk. Sure Marvel probably isn't going to make any other Hulk MCU movies, unfortunately, but they were able to get someone like Mark Ruffalo and was still able to continue the MCU in general and, in ways, people like Mark Ruffalo more than Edward Norton. Or Marvel getting the rights to Spider-Man back and getting him included in Civil War thus connecting his own reboot to the MCU as well.
On the other hand, even now, there's still that feeling that DC is simply trying to copy and play catch up with Marvel after seeing the huge success of the Avengers while figuring that a live-action Justice League could do just as well just as "easily", but the way they're going about doing things doesn't make it look like they have a very deeply thought out plan to accomplish it. I mean, aside from Superman - who already had his own movie with Man of Steel - none of the other Justice League members, as far as I know anyway, are getting their own individual movies until after the actual Justice League movie itself. Otherwise, aside from Batman and Wonder Woman in Batman v. Superman, they're only getting cameos.
One of the reasons the Avengers movies are able to be so full of awesome action compared to character development is because we already get the individual character development in their individual movies leading up to each Avengers movie. That just leaves something that gets them to develop as a team which plays into the action and you are able to root for each character to succeed in whatever they're doing. With Justice League as it currently is going, how are we expected to really care for any of the members outside of Clark, Bruce, and maybe Diana (depending on how much exposure she really gets in Batman v. Superman outside of the battles) at least by people who aren't more hardcore comic book fans? Heck, even Bruce is iffy at the moment, depending on how the movie is able to build him up and all.