It depends on the breed and what the dog is for, I expect. And the kennel set up. I prefer people who keep their dogs in the house, especially in a companion breed. ETA: Also just because a breeder 'uses kennels' doesn't mean the dogs live there. Trey's breeder had a bunch of kennels but the dogs lived inside the majority of the time. When I get a bigger dog, I'll be building a kennel for it to stay in while I'm gone to work. I see it as preferable to crating to be honest.