How do movies like this get a Greenlight?

I'm asking in all seriousness. I have not seen the film nor do I plan to, as I find the premise absurd, but that's just me. I don't care that someone produces a movie that I find to be ludicrous, I just want to know how this is done? How does this happen? How are decent scripts passed over for movies like this or Jupiter Ascending, and on and on and on (the list is never ending). I can't wrap my head around this. You catch whiffs or hints of potentially great movies and/or plots, then they fade into obscurity and Hollywood fills the dead space with dung like this. Is the magic formula to take a classic book, and rip it apart, add several layers of ridiculousness, and then that makes it a hit? Can I just come up with oh I don't know, " The Count of Monte Cristo meets the Hunchback of Notre Dame all while attending Hogwarts fighting off nargles". (BTW - that's my idea - my idea, no stealing it!) I mean WTF - who picked this up and said - "WOW, a classic stuffy romance set to the back drop of Victorian England with, say what now, Zombies! Shut the front door *nameless genius scratches chin* Hmm The walking dead is doing pretty good right now, so I say let's run with it"! Is that how it goes down?