I have a few place settings of "fancy" dishes that I never use -- they're expensive enough that I'm afraid of breaking something AND they can't be washed in the dishwasher. And, at over $100 a place setting, I can't really see the sense in buying MORE dishes that I won't use.
I also have regular, everyday dishes -- nice enough to use for guests, but not so expensive that I'll cry if something gets broken. When I purchased these dishes, I actually purchased more than I wanted so that I would have some extra for breakage. (We have tile floor in the kitchen, hard wood in the dining room and two young children.)
I don't have the time/energy/space to have different dishes for different seasons.