We use crates for at shows, toilet training, traveling in the car and to split bitches up form males when were not in and the bitch is in season.!
I agree with nonnie a cage is only as cruel as you make it, the wrong use/over use of a cage IMO is classed as cruel..
My pups love theres and are not made to in them when we are in the house but will quite happily take them selves of for a short nap
kerry x