Oh, don't misunderstand me. I appreciate the grimdark stuff in the right context. In the realm of Batman? Sure! I'm digging it on Arrow, too. But you need more than JUST grimdark, and Supes has never, ever been about that stuff. Guys like Superman and The Flash have always been beacons of hope (hence why they get zapped into the Blue Lantern Corps during Blackest Night).
So, doing THIS film as all grim Frank Miller Dark Knight Returns stuff...I dunno. I saw that movie. I saw a whole trilogy of that movie. I saw it again, kinda, in Man of Steel. What else ya got, DC? I guess what I'm getting at is that it seems like DC is kind of a one-trick pony in the film arena. They do grimdarkbatmangrimgritty stuff. And...uh....that's it. Marvel, on the other hand, has gone dark at times, but shows far, far more complexity and variety in its films.
As for Watchmen, yeah, it was about as good a translation as you could want to the big screen. But Alan Moore was right that you just miss so much when you don't have the printed page in front of you, at least with that series. Watchmen as a comic series is incredibly layered and detailed. You can study the individual frames and they just have a ton of info in them and convey a ton. The film does a lot of that, but it's just...not the same. Not in a bad way, but it lost something in the translation that I think is really worth preserving. That said, Snyder's translation is as faithful as one could hope for. I even give him a pass on the ending, owing to the realities of film audiences. But even that, I think, lost a LOT of the more subtle aspects of the comic and the social commentary.