This is actually one of the most level-headed interesting discussions on Hans Zimmer to ever take place at Filmtracks. Shame that some try and pull it in the direction of a flame war over someone's natural inclination to slightly exaggerate their opinion and the facts.

Almost every Hollywood composer gets sucked into the expectations and limitations of scoring a major Hollywood film, and their art is restricted as a result. I like to think of it as who can pull off the most emotionally-engaging, dynamic, interesting music with the constraints placed upon them as a component in a money-making venture.

Zimmer's style has NEVER been very complex; even his "greatest scores" (in my opinion, "The Burning Bush" from The Prince of Egypt is his greatest piece) are a variation on a similar technique for developing ideas to that utilized in the Batman films. Much of his style has remained the same because it happened to sync up with the needs of the modern blockbuster, and he has innovated in other areas (electronic manipulation, instrumentation) where he is free to experiment more while still retaining that core style. There is no question that his work has stagnated somewhat as he is able to delegate more and more responsibility to those below him.

In my opinion, Zimmer emulating his own style is no different from a composer like Giacchino emulating John Williams' style. I just listened to John Carter again and it's amazingly unoriginal. Somehow, no one seems to care with a score like that, where the themes are incredibly simple, barely developed, and devoid of innovation. It's simply a matter of people preferring that style to Zimmer's and declaring one to be superior.