Con: We Sort Of Get The Idea Humanity Will Be OK
I once read a review of the
Matrix sequels that said the end of the classic first film negated any need for sequels. If you recall,
The Matrix ends with Neo leaving a threatening message to the machines, saying he will fight back. We never do get to see the actual Matrix destroyed in that movie, but we see that humanity will be fine as long as Neo is on our side. We can fill in the blanks for ourselves. I foresee the same issue coming up with any
World War Z followups. The last scenes I described in which humanity fights back would have been better to save for the sequel. I get the impression those parts were added in case the film was a flop and an opportunity to do a sequel never materialized. They felt out of place with Gerry's "this is not the end" monologue. Since we see humanity fighting back and winning the battles, it's pretty safe to assume that the people of Earth are going to be fine and eliminate the rest of the zombies. There's a scene where we see an entire city of static zombies standing still since there are no more people to infect. This makes them fairly easy to kill off. If all the cities and towns are like that, there won't be many dramatic battle sequences (if the people are smart) and unfortunately for the studio, no obvious open windows for a sequel.