Yes. It's not limited to airports. There are many reason why a hotspot provider in the US wouldn't want the liability of anyone other than a know user accessin

Yes. It's not limited to airports. There are many reason why a hotspot provider in the US wouldn't want the liability of anyone other than a know user accessing their service. These issues are probably more limited elsewhere in the world, although it's probably the case that they are just lagging in coming up with better security practices/policy. Some home internet providers in the US like Comcast have a public WiFi service, but you have to authenticate to use it.