A Lionhead fansite has published an interview with Peter Molyneux:
So - can we talk about Black and White 2? Yeah. You’ve said why you felt it went bad, but what was actually bad about the game itself?
Right. That’s a list, and it’s a list of kinda my failures - which I have to take responsibility for, obviously - but also just the position and situation that we were in and you know, forced to finish the game. And that’s the biggest flaw, not having the time to finish the game. Even though it was in development for a long time. It was rushed at the end, we didn’t have time to balance it and play it.