Peak leisure-travel periods/routes often leave FC as the best value on the plane. The Y fares are high, but sometimes there's some kind of discounted-F fare ("QUP" or whatever) for just a small premium above that.
The regular business travelers aren't there to buy them, so why not the college kids heading home for the holidays? If you don't have elite status and are hauling home 100 pounds of laundry...
