If a vegetarian believes that murdering animals is morally wrong, how can he or she NOT judge carnivores?

While some vegetarians do not eat animals solely for health reasons (which are actually great justifications in themselves for a vegetarian diet), many vegetarians also believe that it is morally wrong for humans to kill animals. Some vegetarians believe that hunting free animals is fine, but that keeping and killing them in the grotesquely inhumane conditions of modern factory farming is morally wrong. Some vegetarians say that they "don't judge" and "respect" other people's decisions to eat animals. How can that be? Eating animals is either wrong or it's not. If it's wrong for a vegetarian to eat animals, then it's wrong for ANYONE to eat animals. If anyone could explain what vegetarians mean when they say they "don't judge," I would greatly appreciate it.