It's just one of those things... different location, different requirements. Inside means you have to consider stuff getting chewed on. Outside means you have to consider predators, heat, and wind. Garage means it might not be a good idea to keep your car in there anymore.
My outside bunnies live inside of "Fort Knox", like Wamplercathy's. They have a fan, and they get visqueen over the one wire wall in winter.
My inside bunnies... well, one of them doesn't chew. He's a wry neck bunny, so his time outside of his carrier is spent sleeping like a donut in some victim's lap for an hour at a time. The other one likes chewing so much, that I had to run chicken wire under the computer workstation to get him away from the wires. :x