I figured out that they meant Tim to get all GrimDark and Batty at the end of his own series when I read this comic. Doesn't mean I have to like it. Although I must say, I've always loved that scene.
Anyway, my issue with DC isn't that they're making Tim all that more manipulative and dark. Tim has always had the potential to be just like Bruce; he's always been good at compartmentalizing his life, understands shades of gray a lot better than Dick and has a certain determination to do what is necessary without being hampered by emotion. This is why Tim has never been the "everyman" sort of character Dick has always been, even at his angstiest. At first glance, it looks like Tim's following closely in Dick's footsteps, but when you take a closer look at his relationship with his teammates in YJ and the Teen Titans, you see that it's a lot more distant and authoritative than Dick ever was.
This is why Tim is the natural successor to the Bat, rther than Dick. For Dick Grayson to adopt the kind of withdrawn persona that is the Bat would be a corruption of all that is fundamental to his character - light, optimism, the need for tangible love and acceptance and untempered emotion.