Oh, one last thing. A werewolf is a human who transforms into a wolf at the sight of the full moon, and who transforms back afterward. So killing a werewolf means you’re ultimately killing a person. Zombies though are not people, well not anymore. They will not transform back to regular people. Maybe this plays into why we prefer zombies over werewolves.
Personally I don’t think werewolves will ever be in style to the level that zombies are. Werewolves are often more sympathetic creatures, such as Lupin in the Harry Potter books. Zombies, on the other hand, are a clear cut case of bad things. No zombie ever wants to do nice things to you, well except for the mutants in Fallout, but they’re not really zombies per se.