The point is that WB would want to do this regardless, because they can make a lot of money.thus why they're trying to bring back Bale.
Also, I don't think it would take an entire movie to explain him coming back to Gotham. At least I don't think WB would see it that way.
They're basically putting money before quality. Perfectly understandable that WB does it since they're a studio and that comes first but it seems to me that a lot of people here are in favor of that as well. From the way they word their posts, it sounds to me like a lot of people here are happy of the fact that quality is being put aside in favor of money and in favor of Bale coming back. That's the part that ticks me the most. Unless they work for WB, why would any fan want that since they will be the ones spending their money to see the movie and hope for it to be good?
I still fail to see why the new Batman can't be just as big of a cash cow or an even bigger one than Nolan's Batman once he is established in the first movie he appears in (which will be either a Batman reboot or the first JL film). After his first appearance, there is no reason he can't bring in the same money if he is written well and acted well.
Also, see the first link in my signature. I explain why rebooting Batman will be better for WB financially in the long run. Not to mention that WB doesn't want to ruin their relationship with Nolan who makes tons of money for them.