Don't kid yourself. Its always about money. The reason why WB is so gung ho with this dark approach is b/c B&R was an absolute disaster that was purely attributable to a creative direction that no one liked. They expected Begins to be a moderate success b/c of the baggage from the previous film. Now that people have resoundingly embraced the dark approach to Batman, WB is going to be the biggest supporter of everything dark and adopt other franchies in a similar vein which was confirmed by Robinov's comments.
When it comes to corporate entities they are in the business to make money. If something makes money they will follow it regardless of what the true fans think. Its not about faith, its about the results. That's what shareholders are interested in. You can bet the farm if B&R made boatloads of money, we would have seen 3 more sequels in the same campy tone. The epiphany WB had wasn't about being true to the comic roots, it was about a business plan that went horribly wrong in 1997 and the decision to go in the opposite direction with Chris Nolan b/c that was the only path they saw as viable for a franchise as potentially profitable as Batman. Just be glad that we the fans are lucky the stars aligned up just right and the Studio, director, and creative direction of the film are all going in the same direction. This type of event rarely happens and we should be glad it happened to Batman.