Funny, when you compare the Batman Returns score to Batman, it's anything but a copy and paste. I mean, the Batman theme is still there, but arranged differently, and there are all sorts of new themes to go along with it as well as new action cues. However, you look at the Zimmer/Howard scores of TDK and TDKR and there are a lot of themes and cues from Begins that were reused(like the monorail fight track from Begins being reused when Talia crashes the truck in Rises).
Now I know where you were going with that, yes, Elfman's style can be identified a mile away. Why's his music always gotta be so goshdarn SILLY? But that can be said for a lot of composers, some of the best really. Williams scores are almost instantly identifiable in many of his films and have recurring elements, so does Goldsmith, Silvestri(the Predator movies sound very Back to the Future at times), and so on. But at the same time, I don't think he's given enough credit for his versatility. They say his style isn't innovative or intricate enough compared to Zimmer and Junkie XL, then in the same breath, people complain about how weird and whimsical his stuff is. They want innovation, but they don't want anything weird. And that in of itself is a big problem with superhero and comic book fans. They want so badly for their favorite stories to be taken seriously even though superheroes are supposed to be odd and unusual.