Well, if you're a film director and you're worried about fan reactions, to the point of slavish devotion, you shouldn't be making movies in the first place. Because at the end of the day if you're a director you're making these movies for yourself and for the big fat paycheck that's gonna come in the mail.
If you want to keep making the money though, you have to concede to some fan and studio demands. Most directors don't just say "screw the script, let me tell you how I've envisioned this" most who do, tend to be the ones who don't get a chance to make a sequel.
The issue here is that if a director tackled a new film and fans end up hating it and the film bombs, you're going to have a hard time finding work afterwards or be forever reminded of your turd of a film. Considering how well Dark Knight did, Nolan himself has to worry about the new film being a success. Generally, it's intimidating for any creative producer to tackle an old IP that has been done extremely well. Regardless of coming up with your own unique and fun vision, it will still be compared to the old versions and consequently get an unfair rep because it doesn't live up to the unrealistic expectations and nostalgia vision of the older fan base.