The value proposition of a dog as a pet or as a working dog is much, much higher than keeping them for meat. They've been domesticated for hundreds of years and are loyal, easy to train, and smart enough for useful tasks. They also can be vicious defenders of your property, your kids, etc.

The value proposition for pork is really good. Pigs are huge, yield a lot of meat, meat considered safe and desirable by Westerners, etc.