Dudes, maybe this isn't such a good thing?
Think about it. Davis loves his Predators. Sure, he was responsible for getting two really, really shitty Pred-related movies made, and let's face it, the first two were pretty obviously what they were thanks to Joel Silver, not Davis.
But when the guy had more creative input onto a Pred-related film, he basically engineered it towards giving Pred fanboys exactly what they wanted - a Predator who walked all over Aliens in between awesome poses. He knew what Pred fans wanted, and handed it to them.
I'm not saying Davis is awesome, or even good, but if he was on-board then Predator fans, at least, would likely be catered to, come what may. And heck, maybe if they finally hired a decent writer, Davis' unapologetic fandome, coupled with a solid script, could actually result in a movie that pleases both the mindless crowds and Predator fans.
Instead we have the starting point of the movie being a script that nobody who's read it has had anything decent to say about it, except, obviously, people in Hollywood, who largely wouldn't know a good idea if it bit them on the face.