Yeah, but Marvel/Disney has embraced the more hokey elements of their comic book characters. So far with WB it always seems like they try to keep the hokier elements at arms length.
Well, it's relative. Marvel does tend to avoid using the superhero nicknames, and tries to achieve a "grounded" feel for things and rationalize magic as alien technology. So there are some things that both franchises do to make the comics concepts more accessible to a general audience.
Also, one way in which Marvel is even less authentic than DC in its movies is the heroes' attitude toward killing. Batman and Superman at least showed some reluctance to kill most of the time, but Iron Man, Cap, and the rest are all quite lethal, unlike their comics counterparts.
And are we talking about WB as a whole or just the Nolan-produced DC films? I'd say the Green Lantern movie went pretty much whole hog with embracing the way-out and hokey ideas; if anything, its problem was that it overdid the borrowing from the source and overloaded the movie with continuity and backstory.
I think the tone of the movie had a lot of problems with it, but I agree with you. I think if the GL movie just had Abin Sur and maybe Sinestro, and spent its time on Earth, it would have made for a much better cinematic introduction to the hero.
Oa, the guardians and the corps could easily have been fleshed out in a sequel.