I think both films were created by people who absolutely failed to understand Superman. While Superman Returns was a bad Superman film, it tried hard to actually be a Superman film. It failed, yes, but it was absolutely trying to be a Superman movie.
Man of Steel is not a Superman film. The people behind it do not understand Superman and the same people are behind Batman v Superman. It will be crappy in precisely the same way as MoS. The entire point of pairing the two characters is that they are opposites.
Both Batman and Superman in the Snyder-verse are basically the same person, i.e. men with tragic pasts with broken psyches (Batman by rage, Kal by fear) who can't solve any of their problems without murdering their opponents.
While a soft case can be made for Batman being little more than a crazy vigilante (although why anyone wants to see that is beyond me) a fearful Superman, one who can't outthink his villains is not Superman.