The tone on display is only part of the movie. The hopeless, helpless despair of people's imaginations being crushed by him. It sets up his doubt - making him wonder if he truly is doing more harm than good.
Batman adding his angst to the shyt, which has made him a prick that no longer cares what he's become, which is something that's hopeless himself, will begin be the test Superman steps to. The true fight will be the ideals both push upon one another, to the point where Batman fades further into that pit, and Superman might be near falling in.
Then, the gawdess appears, proceeds to slap the shyt out of both these nikkas, then teaches Superman that his symbol of hope is what he must live up to,
while throwing the sweet, amazonian puss Batman's way, and bringing him back to the fight he's been hoping would kill him for years now.
I'm ready!