Batman V Superman' Ultimate Cut Releases July 16

[Austin Manning]

If they ("No YOU'RE a dangerous killer", right?) are well defined and believable, why did Lex feel the need to generate more reasons? It's because David Goyer came up with several conflicting motivations and was too incompetent to settle on something that makes sense.

Batman believed Superman was dangerous yes, but at the same time he saw Superman actively save people in BvS and in the 2 year gap between it and MoS. Trying to rationalize his viewpoint with Superman's actions (and a lack of Kryptonite weapons) is why he doesn't actually try to fight Superman earlier in the film. Superman on the other had feels that Batman is a menace, but not someone he needs to fight due to the power difference between them. He basically tries to intimidate Batman out of crime fighting and considers that the end of their conflict. While they certainly didn't like each other, they weren't at the point of having an all out battle to the death.

Lex recognizes this and actively tries to escalate the conflict by engineering a serious of terrorist actions, then taunting Bruce and blackmailing Clarke.