If you couldn't figure out Lex's motivation for most of his actions, you weren't paying attention.
Re: Kevin Smith, his own previous comments regarding BvS bely the idea that he hadn't seen or been aware of the film's take on both Batman and Superman prior to its official release.
Don't be mean, Digfic, be helpful.
Explain what you think Lex Luthor's motivations were, what his plans were, and how he was supposed to walk away from anything that we saw with out being branded public enemy number one?
Personally I think that his plan was evolving as the story continued, and what ever safe haven perfect crime he had foreseen for himself months earlier was sabotaged by his own insanity and sacrificing himself was okay, as long as him message was delivered. However if he was insane, why isn't Luthor in a funny farm?
Yes, I heard all that stuff about proving that gods were demons that heroes were villians and it directly related to conversations we didn't see between Lex and his father, and Lex was hell bent to prove his fathers moral compass and religion wrong, even though Aliens are not gods, and almost no one thought that Superman was an Angel, but yes that was fricking subtext about his childhood, and he's a grown ass man who should be on medication and have a couple therapists to deal with that shit.
If above is what was guiding him, the missing scene that would pull the movie together was 8 year old Lex Luthor being forced to look at the painting of paradise lost while his father whipped or raped him for being a sinner while manically screaming bible quotes about the power of the lord to deliver sinners... Which wasn't even hinted at.
Although the Luthors had to have done something silly, for their son to have murdered them.