Is it wrong to use a "dog crate" for a place for a dog to sleep???

I have a large breed dog and I have an extra large dog crate from a store like L.L.Bean, it is supposedley for up to a saint bernard size dog. My dog likes it cause it keeps him warm in the winter and cool in the summer, it is in the house. My friends say that this is a horrible, cruel, and wrong thing to do... However I find this ridiculous cause they may let their dog run around the house 24/7 but whenever their dog climbs on the sofa or does anything they do not like then they yell at their dog and bop it on the snout. This does nothing.... their dog still makes a mess and goes where they don't want him too. But mine always goes happily to the crate and gets a treat. He always stays by my side when I take him out. So what I'm asking for is your opinion.