] And there you have it. Cleanliness takes work, and work in those days meant servants. If JA is to be believed, ladies were out and about a good deal more than you imply -- the Bennet girls traipsing about the countryside, and the Dashwoods paying calls around London. The world is made of dirt, and a woman in a long dress who goes out in it will invariably get dirty, not to mention the lingering olfactory effect of the healthy glow of exercise.
It seemed to me that it might have been easier to keep a nice dress clean (at least on the *inside* because so many layers (albeit thin layers) were worn underneath, and so there was only the worry to keep the outside clean.