"I feel like you need to get Superman a little further down the road before you can do a Justice League movie.... All I’m saying is that you’ve got to get Superman further down the road," Zack Snyder said that year. Turns out they never went down that road. They never even got out of the garage before blowing the door down with an explosion of upcoming superhero flicks.
But Russell Crowe in a conversation with Digital Spy, recalls that there were supposed to be Man of Steel sequels first before all of this Justice League stuff went down. It also explains why he wasn't asked to return as Jor-El in 'Batman v Superman'...
"Originally — I could be completely wrong — I think there was a number of Superman movies. But I think they made the decision to jump past those and go to the idea of Batman and Superman in the same film. So, no, I didn’t have any discussions about that at all."
Frankly, I think they screwed up by not continuing to tell Superman's story for a while, especially since they were charting such a new direction for the character. What's done is done, and there's still a chance more sequels could happen at some point if Warner Bros. gets their act together.