Crates are a must in my house. I rehabilitate ex-fighting dogs, dogs with high prey drives and dogs who like to eat knives.
These dogs are in their crates 10 hours a day minimum. If I let them all loose I would come home to a house full of dead dogs.
I also have a dog that if she's not in her crate, she'll open drawers and pull out knives and chew on the blade.
Crates are great devices to make sure animals are kept safe.