A few weeks after Snyder was revealed as Director, IIRC.
It's why, although I don't have a whole lot of faith in this new movie, I'm not envious of them. Because no matter what direction you go (all new narrative or a Singer-like continuation of the '78 film), you will always be compared to the Donner film... from acting, to score, ETC.
So the guys are screwed no matter which way they go; because it'll be hard to top what is arguably one of all time great film scores (the only score that beats it, IMO, is the Lawrence of Arabia score...) and if they just riff on it, they'll get crap for it too.
Personally, I'm more worried/pissed about the fact that instead of trying to really make a different and distinct looking Krypton (which is why I've always loved the Donner version... because a crystalline world IS a unique and out there visual), they've been quoted that the Krypton of this movie is going to be like Coruscant from Star Wars.
So you're throwing away a unique visual (and vastly under-explored technology) for a generic city-scape from another film. Whoopie.
Well, I'm in the minority here. If I was the director, I'd want to incorporate as much as possible, rather than bring a broom, but perhaps the past films are just too much to reconcile with a new one. For the first time ever, I honestly feel that I'm becoming too old for this stuff.