@NJ99221 : Because some of us live alone, and only eat so much salad a day. Bags make it easier to get a bit of variety. I still wash and spin mine, but realize that doesn't get the really nasty bugs off.
I have a salad for a light meal once a day, it's good to eat raw foods, healthy. Bagged doesn't seem to last, almost have to eat on the same day as bought. I too wash and dry with paper towels, though never eat it all, and end up throwing out wilted leaves. Crunch of a fresh salad is so good!
Then there are some of us who grow their own. There is also Fiti, which is a fruit and vegetable wash. Unfortunately, with the way food is grown, and then washed, the same water for batch after batch, contamination is unavoidable. Cut up a dirty product and the bacteria spreads through cut edges. You can grow lettuce even in a pot, you don't have to have a whole garden.
@susieq : I literally don't have a single square inch of direct sun now. I bought a couple of Aerogardens for growing things inside, I have kitchen herbs, strawberries ('cause it sounded like fun), cherry tomatoes and alyssum for color. Lettuce does well in them, too, and I'm going to try that again, next. I'm toying with the idea of buying one more unit while these sales are going on.