I definitely think a lot of the criticism of the film is coming from people's projections and expectations of the characters...ie "THIS is who Superman is". Whereas this film takes liberties with the characters for this universe. Batman kills bad guys seemingly. And is generally much darker and violent than any other live action Batman, but in a believable way, as weird as that sounds. Same goes for Supes.
It's all about what these characters might actually be like in the real world IMO.
Like I said earlier if batman kills people the suicide squad movie shouldn't even exist. In the real world the joker would be dead.