I'd rather wash clothes every evening than carry a bunch of luggage. If there is a convenient washer/dryer around, I use those, but otherwise I handwash the clothing in the sink.
It is just my husband and myself, but we can get away with very few little luggage. I take very light clothing (layer it if it gets cold), and sink wash everything we wear. Squeeze it dry in a towel and hang to dry. By the next morning I have all clean clothes again. I pack two outfits, so an extra is always dry. I do like to pack extra underwear and an extra t-shirt in case of wanting to change more than once a day.
I also agree with the comment above about not liking dirty laundry in the room. Another factor for me is that when I get home from a vacation I don't like to have piles of laundry needing to be done.