Hey, Jim, don't put words in my mouth. I'm not trying to use any of this as justifications for lower wages. I'm just saying that it's gotta be the whole banana or else it's just throwing money out the door.
tadjr, you're right that the 20 min turn has increased by about 25%, in part because the average number of seats per plane has increased by about 25%. Which, of course, brings us to your bigger plane comment.
Of course a bigger plane needs more person-hours. But that should be (roughly) compensated by the larger number of seats, so the CASM associated with ground service would otherwise remain similar.
WN's point to point network does reduce the number of online connection bags, and their lack of interline does reduce costs somewhat (incidentally, do you have a sense of what percentage of bags go interline anymore?). Some of these sorts of costs (e.g., interline) provide benefits to the customer, and thus can be covered by higher fares. How much more does it cost to provide these services? I'd sure love to know; it'd give us a much better sense of whether or not the customers are willing to pay for these services.