Oh yeah, forgot about 28 Days Later. Not quite a spoiler for anyone who's seen the sequel 28 Weeks Later. But in those, I remember people involved with making the film insisting those running "zombies" weren't zombies but "infected".
I think the general premise of such films is that, in the event of an actual widespread outbreak, the chances of survival in just about any civilized area would quickly drop to a very low number, in a very short duration of time. Usually, the survival time until the last survivor dies is not greater than the natural timer until the zombies decay past a certain critical point. In other words, no one lives long enough usually to see zombies break apart.
