I guess you are right, can't fault them for trying to get away from the dreaded radiation from space. Like I said before though, it's not the idea it's the fact they seem to have changed genre between films. If it where a totally different film I wouldn't lament the demon/zombie idea...actually that sounds awesome, there is plenty of room for all manner o fucked up there, but it is a sequel that didn't really have this stuff in the first film. They didn't crawl on the ceiling or mimic humans, so why are they doing it now?? I don't mind a movie having weird rules for there zombies, I just need them to be consistent between the first and second film.
I do see your point though, doesn't matter if it is supernatural demon virus or radiation from space, they are still zombies to me...but if they are demon/zombies I want to hear one moan "SOULS", it would make me laugh
On an unrelated note, I miss the spell check