This isn't rocket science. He said he planned to do it, was writing a script, and wasn't a guy who will make a movie if it's not great. He said this at a time we all knew the studio was pushing for a start-date and release-date that he'd literally publicly admitted might not conform to his own time-table, he noted he was trying to be ready when they wanted but couldn't guarantee it because he wasn't going to do it til he was sure the script was good enough. So during that time of studio pushing to move faster, and the fans and press acting anxious for him to hurry and get into a Batman movie, he noted that hey, he's not gonna do it if it's not going to be great, and that he didn't feel the script was at that level yet.
It's very clear he's always said he was writing the script, he always said he wants to make it, he's always said he plans to make it, and he only a few times -- during those times when studio and fan and press pressure wouldn't just take "I'm working on it, give me time" as a simple answer, that he wouldn't be pushed into a faster time-table than he was ready for because he will only do a film if he thinks it can be great, ESPECIALLY his own solo Batman film that will be judged against all other Batman films and as a supposed safety-prop-up for the DCU.
He is making it perfectly clear, for anyone being reasonable and listening seriously, what's happening and why, and the claims that somehow he's just dancing all over the place with mixed signals and totally responsible for confusing the heck out of everyone etc etc etc is just trying to sell snake-oil, period.