Because whatever you eat in your culture is disgusting in another culture, For example koreans eating live sea food is gross and angering in other cultures, everyone outside of the middle east (and other muslim countries) eating pork is wierd(and banned) in muslim majority countries, the world is a big place so opinions float around everywhere, do i think eating dog is right? No. Especially the way they prepare them in china, Dogs and cats are also extremely difficult to have them similarly to livestock, They're both carnivores, they need meat to actually have good quality meat(and survive) which would be expensive, so eating dog or cat wont be efficient, normalised, or common, ever. Now "What makes a dog's life more valuable than other animals?" Lets say pigs for example since they're compared to dogs by most vegans, Will a pig help soldiers in a battlefield? Will a pig be trained as a service animal? Will a pig defend its owner against an armed robber? Will a pig protect the house at night? Will a pig help cops similar to a k9 unit? Dogs are more valuable to us humans, But to nature they're equal.