They aren't mean anymore, see?

United Airlines Resurrects Its “Fly The Friendly Skies” Tag Line

Perhaps the skies have felt particularly unfriendly since 1996. That might be because United Airlines retired its “Fly the Friendly Skies” tag line that year, and has since had a rough slide into passenger grumpiness — after all, it receives more passenger complaints than any other airlines. But that’s all going to change, United hopes, by resurrecting that old line. [More]