Years ago I did think that crating your dog was cruel. However, that all changed with the addition of our much loved dog Daisy. Daisy is a little dog, a border terrier, who was so teeny tiny as a puppy that I would have thought crating her would have been very cruel. After thoroughly researching the breed and finding a reputable breeder and meeting with her a few times one of the things she really believed in was crate training. She had seven of her own border terriers that she raised this way so I listened to her experience. The theory with crate training is that a dog will not go to the bathroom where they sleep. When you have a puppy they start off by sleeping in the crate so that they aren't doing their business all over the house. As soon as we would let Daisy out of the crate we would take her outside to do her business. She learned very quickly not to go to the bathroom inside her crate which quickly translated into not going to the bathroom inside of our house. I was amazed at how effective this type of training turned out to be.
Crating your dog is only cruel if you don't use the crate properly. To learn how to use a crate either talk with your veterinarian, a reputable breeder or read up on it. Since there are many places to learn how to use a crate there really is no reason why it would be cruel to crate your dog if you follow the recommendations correctly.
Let me tell you about an added benefit to crating your dog. Our son was 5 years old when we got Daisy. We established the rule that whenever Daisy was in her crate we were to leave her alone. We explained that the crate was her own space, like her own little room. What we found was that Daisy would go in her crate on her own just to hang out, rest and gather up her puppy energy. We would leave the door open so she could go in and out as she wanted to. To this day, 10 years later, Daisy still goes into her crate on a daily basis for some alone time. She finds great comfort in it. I guess like humans even dogs need some time and space to themselves.
Although I originally was under the impression that crate training was cruel I became a true believer in crate training based on my own personal experience. If you check out the facts and use a crate properly I believe that a crate is an incredibly efficient tool in helping house break your dog with the added benefit of a special place for the dog to hang out.