Indeed. I don't love Comcast - they are robbers who have tried to screw me so many gd times during a recent move across country, and if any other broadband in our area was any better we'd have dumped them. But, that said, this is an awfully nice perk of being their customer. Currently I'm working on Boston while my family lives in CA. We have xfinity at the house in CA (I bought my own modem for $60 and had a really good router. Renting a modem is just dumb), and I get Wifi in Boston off of my neighbors. It's a bit wonky in that for some reason my desktop can't log in, but if I USB-tether my phone or tablet to the desktop it works. (Any ideas on why that would be?). I can walk through any residential neighborhood in the city and I've got wifi.
You can get all worked up about vague security issues or extremely minor power usage, but really, this is a pretty nice and useful feature if you're their customer.