At least according to io9: The Most Discouraging Justice League Rumor Imaginable.
Brett Ratner isn't a paragon of a human being, we know that. Honestly, I don't care. Lots of people are assholes and still make good entertainment.
He's not inspired, but he is a competent, no-surprises director who understands pacing. I've said it before, and I'll say it again, Ratner was NOT the problem on X-Men: The Last Stand. His directing credits are all pretty watchable, high-concept fluff, with some high points. The Family Man is good, Red Dragon is (surprisingly) quite good (unless you insist on comparing it to Manhunter. I try to take each film on it's own terms), After the Sunset is fun, even if all of those films are clearly "it made money before, make something similar" studio films. And the Rush Hour movies are exactly the kind of high-value, slicky-made entertainments that Marvel is making right now.
The problem with The Last Stand (which is a good comparison, since it's his only other superhero credit) was that Fox was pissed that Bryan Singer (who's, to this day, the ONLY filmmaker who's had a handle on how to do the X-Men) for doing Superman Returns (far better than people give it credit for, but too beholden to Richard Donner's film) and dumped him. They went with a poor script, which Matthew Vaughan- yes, X-Men: First Class (which, it should be noted, had a script co-developed with Singer) Matthew Vaughan, oversaw putting together. A script that checked off fanboy "want list" crap over a cohesive vision. Ratner, was hired VERY late on that film...Fox had a script and a release date, and Vaughan freaked and quit.
I will never call The Last Stand the best X-Men movie, but it is watchable, and the set pieces are well executed and exciting. It also feels connected with Singer's first two films. Ratner understood what he needed to do with that script, not step on the toes of what worked before, what was expected, and keep the shit moving. He's not an auteur, he's not even a "great" director, but he is a workmanlike one. I imagine that if he had come up during the days of the studio system he'd be a "go-to" guy.
Compared to Joss Whedon (if we do a direct Avengers/JLA comparison)...Ratner can't touch him on concepts, scripts, writing, but there's already a script in play. What Warner's wants is a pure director, and on a pure technical level, the nuts and blots of filmmaking, I think Ratner's equal to, or even a bit stronger than, Joss (even if The Avengers was a big step forward for him).
So, yeah...I understand why they're looking at him. I wouldn't even be upset if he got the job, because, if he does it, the chances of it actually getting made probably double. It'll be fun to watch, and probably faithful to what works. The real question is the script, which is what really made The Avengers memorable.
Do I wish they'd find somebody really exciting, with a non-corporate sensibility to really invigorate the JL? Oh. you bet! Justice League's current screenwriter, Will Beall's got a lot of heat coming off Gangster Squad, so I expect it's an exciting script (faithful, "good," or "the right script?" Who knows?).
Ben Affleck (who's a GREAT director waiting for the world to realize it) clearly didn't want it. The Wachowskis are NEVER going to do it. Zack Snyder apparently wants it, but that's because he's exactly what Ratner is, but with visual flair (even if it's cliche visual flair).
Although, that said...the Man of Steel teaser is really awesome.
Look at who Marvel's been using; Jon Favreau, who was fully B-list (if that) before Iron Man, really (and after Cowboys and Aliens, may be again). Kenneth Branagh, who was hardly known for this sort of thing. Joe Johnston, who I think is a fantastic, bordering on genius, workman director, but also has a "hack" label. Whedon, who we know is a genius, but he's a TV guy with one flop film and some internet stuff. Shane Black, a huge screenwriter from 15 years ago, who fell off the map, then made possibly the best film of the 2000's - that nobody saw. They all made great-to-fantastic films.
Honestly, I don't think you can do the shared universe thing with filmmakers with strong visions and things to say. Christopher Nolan, for example, wouldn't want to, and I think, flatly, he couldn't. He wanted to work with themes and psychological elements that would be completely invalidated the second Christian Bale's Batman walked into a JLA meeting room. The saddest thing, to me, is that kind of vision, that kind of pushing at the concept, thanks to Marvel, is dead and gone. Hollywood is fixated on "team 'em up" now.
Yes, Wheadon...who definitely had a strong vision, but what he wanted to say was "gee whiz! The Marvel Universe is neato!!" I think he looks at this like working on a TV show...you can make very, very fun, exciting drama, but, except in VERY rare cases, you're not going to be transcendent. Which is probably the healthiest place to be, and those checks will pay for his Much Ado, and the Dr. Horrible follow-up.
Andrew Stanton hadn't so quickly slunk back to PIXAR for Finding Nemo 2 after the pounding he took over John Carter (a top-ten movie for 2012 in my book...screw the box office). He would be an excellent choice for Justice League, or heck, what about Brad Bird? The Incredibles is still one of the best superhero movies ever made, and flat-out the Best fantastic Four movie. I think he proved himself completely with Mission Impossible: Ghost Protocol. These are both mid-tier guys who might take the job as another stepping stone, and represent clear, strong visions of the properties they tackle.