Midori, as usual, you are being your open-minded pleasant self. So anyone who brings up their dog contrary to your beliefs is somehow abusing their dog.
Even dogs that have a kennel, may prefer to sleep outside if the weather is ok. What might be cold for us, may be just pleasant for a dog, depending on the breed.
I can just say from my experience of having friends whose dogs sleep outside, they are usually well loved family pets and are well socialised. In fact, many of these dogs seem more chilled out and comfortable around humans and other dogs than some of their canine counterparts in the UK 
Also, when my dog stays with my friends, she sleeps outside. When their dogs stay with me, they sleep inside. The dogs pretty quickly adjust to the new sleeping arrangements. It is harder when your dog has been sleeping inside for many years. But it is just an adjustment, I don't think it will lead to any major issues as long as they get family time during the day.
One thing which works for me, is that in every room where the dog is allowed, I have a towel or mat which is the dog's bed. She automatically goes to her bed while we are in the room. We are together that way, yet she is limited to one part of the room. Very useful too, when we are visiting people and we just have to say Bxx go to bed and she will go and relax on any towel or mat that is in the room.