I noticed how in TDK since his character shared the limelight with Joker and Dent/Two-Face this sentiment has come up. He was pretty well beloved in BB in which he was the lead character and really everyone in that movie circled around Bruce Wayne/Batman and his arc. HIs arc and growth was that movie, the villains and supporting cast and even macguffin plot in the third act were all secondary.
But now that the story is the main focus of TDK and Batman is a player in it, people aren't as happy with his performance as the newness has worn off, even though I think in TDK he just inhabited the Batman persona and I never once thought "that's Bale playing Batman well," but just thought "Batman."
I think my prediction in another thread will come true. BB3 won't be as good as TDK and even if it is a good movie fans will backlash in disappointment and ***** about Nolan's realism take and how he doesn't get the character and "fantasy" of it. And the things that just are nitpicks now will become full fledged attacks against all the films. They'll turn the bat-suit, the applied make-up, the Chicago-is-Gotham angle and Bale's voice will become huge liabilities to the series. And the fans will turn on Bale and hate him saying he "doesn't get the character."
Look no further than what happened to Raimi and Maguire. Yeah Nolan's Batman movies are better, but they're following the same pattern. Beloved and "flawless" in fan community eyes in BB, even better, but worthy of nitpick criticism in the second and the third will be inferior and then comes the "they don't get Batman, we need a reboot!" threads.
I'm counting on it.