Marvel needs to focus on something that just became big to diehard comic fans in the last decade instead of a classic powerhouse that nonreaders recognize? That's pretty short-sighted.

The fact that the followup film is "Secret War" implies strongly that ALL universes including 616 will stop existing. Secret Wars have always taken place in a variation of Battle world and lastly because of an Incursion between universes. If 616 isn't destroyed in Doomsday, then I'm not sure what Secret Wars would even be about.