We're really getting waaaay into Non-Food here, but the price of short-term wireless contracts are absurd:
$10/day in better clas hotels, Starbucks, while it's free at the Motel 6, Panera, your local library... there's some very silly economics going on.
Frankly, I'd give up a bunch of my frequent flyer rights if United or American would provide me free wi-fi in their terminals, but the airport authorities would complain about their lost revenues.
I'm more likely to buy something to eat (ah, food related) in a Panera if I'm going to get free wireless than I would feel obligated to buy something after shelling out $10 for a couple hours elsewhere.
There were a couple times on vacation that my kids freeloaded off a bookstore or something in order to IM while MrsF and I shopped or ate somewhere nearby. They were public hotspots, though, not unsecured open private nets.
But you're right: an encrypted net isn't going to protect you as a wireless user one iota -- use your firewall, antispyware, etc. I disagree that it's useless, though: WPA is pretty good encryption to protect the inside from the outside -- you don't want just anybody on your network.
What is patriotism, but the love of good things we ate in our childhood?
-- Lin Yutang