I think this was a good decision as it gives the dev team more creative freedom and legal invulnerability whilst ensuring Dungeon Keeper stands alone in its unique and unadulterated state.
Having commenced the War for the Overworld project all those years ago, I would've been completely against commercialising it. However, it won't be using the original DK IP and if the team who have put a hell of a lot of time and effort into developing it decide this is the right decision then there really isn't much to argue about. Both these points do, however, put WftO's status on the KK forum into question though. Should a purchasable game that is increasingly holding less similarities to Dungeon Keeper hold such a prominent place on the forum if any at all?