My first set of chicks I kept in the house in a brooder for 4 weeks. That was all I could stand it! The dust those little ones make is unbelievable! How it coats absolutely everything is beyond me.
With my second set, I set up my brooder in the garage. MUCH BETTER!
Though I will say, I did have a pullet who at nine weeks came down with what I believe was Marek's (even though she was vaccinated) and until I made the decision to euthanize her, I kept her in my mud room! She ended up being in there like 5 days. She was too cute. She would try so hard to "come running" when she saw me. Her poor little legs, though, they just stopped working!
Anyway, I digress, I agree, chickens should be allowed to live outside and be a chicken.