Wait... why? They just did Batman reboot not too long ago and so far, its sequels seem to be doing pretty well. Batman begins came after a long absence of live-action Batman movies, and the main reason for said absence was... well, I think the fact that the last movie in the previous Batman movie series had Arnold Schwarzenegger as Mr. Freeze speaks for itself. I mean, I like Schwarzenegger, but I simply can't take him fighting Batman as a villain who freezes people and makes horrible ice related puns seriously, and the other things in the movie weren't any better, especially when compared to the much darker tone the first and second movie had. Once you introduce the Bat Credit Card into your movie series, a reboot is the only hope, but the current series seems to be doing pretty well so far, and even if the third movie actually became a huge failure, you usually weight until after that happens before deciding that the series has no hope, and even then, you'd probably want to weight some time before actually starting anew. I mean, we already saw the events leading up to Bruce Wayn becoming Batman when we saw Batman Begins, our memories aren't that bad, you don't need to remind us how Batman started so soon. If Hollywood wants another Batman movie, it seems to me that they could just continue the current series.
The reboot is so that they can do a Justice League movie.
Nolan's Batman, while awesome, doesn't really fit in the same world as Superman/etc.
I suppose if that's the reason, I could sort of understand it better, because I certainly can't imagine Superman, Wonder Woman and what not existing in the same world as the most recent Batman movies, still, I don't think that necessarily requires rebooting the franchise, at this point, people who would watch the movie probably already know who Batman is, so you can probably just have him show up without explaining his origin again and make it still make sense, as long as you make it clear that the movie isn't connected to the other Batman films, if you want to proceed it with movies introducing characters who would appear, I'd think characters who haven't had movies made about them recently should be the first priority, since mainstream viewers might not know who they are, but hey, that's just me.