What is wrong with keeping dogs outside?
I have had both inside dogs, outside dogs, and inside/outside dogs. As long as the dog has adequate shelter for heat, cold and rain, there really is no problem with it. Dogs are pack animals and require interaction every day. It sounds like you are doing that with your dog. Dogs are animals and NOT people. A lot of people seem to forget this and think all breeds of dogs need to be in the house all the time. As long as the dog has a place to go to keep warm or cool and out of the elements, you are doing fine by playing with him every day and bringing him in during a storm (although most dogs are fine in a dog house or shed with a door). Keep doing what you are doing and tell your friends that if they are worried, they should be doing the research, not you.