I frankly find some of the negative reactions ridiculous, particularly those calling it entirely grim and dark, devoid of hope etc. It's so funny considering how after MoS one of the main criticisms was that the destruction and damage in the aftermath of Supes' and Zod's fight was never addressed and everything seemed to be neatly swept under the rug, whereas now the trailer has demonstrated clearly that could not be further from the truth, and that precisely this theme will be front and center of BvS in its entirety.
MoS had several cheerful and hopeful moments, and I have no doubt that this film will have them too, it's just that some people need to face it, the DCCU IS and WILL be heavy with drama, much heavier than the MCU, and that's fine. WB is taking a different approach, in the sense that drama and negativity is as much a part of life as happiness and hope, just that with larger than life characters like Superman, the good AND the bad naturally has to be extrapolated to the nth degree.
I don't want to make this a Marvel vs DC thing, I've been a Marvel fan arguably from an earlier age than I've been a DC fan, mostly focused on Spider-Man and Daredevil, since age 8. I've only grown to appreciate the DC pantheon many years later, but just looking at the movie universes themselves, I can say that at no point during any of the MCU films so far, apart from parts of TWS, have I really felt that anything is ACTUALLY at stake or could go horribly wrong in their cinematic world. I still enjoyed all of them, but for the life of me I can't bring myself to try and re-watch them, because I can scarcely find any nuance in there, or anything that would really make me think about life. I still watched and thoroughly enjoyed all of them, but found them too easy to forget about afterwards.
That wasn't the case with MoS, and certainly doesn't seem like it will be the case with BvS.
Just expressing a personal opinion here, not preaching the objective truth or trying to start a flame war.