what do you not understand?

Why would I want my WiFi to be contactable?

A lot of people don't talk to their neighbours. This has the potential to have lots of social benefits. You could contact people in your vicinity about lost pets, garage sales, etc. beyond just sharing a wifi connection. Maybe you could even help a neighbour have a better connection by letting them know that they should change their WiFi channel.

There must be a better way to do that.

It's about people being nice and sharing with each other. Like Couch Surfing perhaps. There doesn't have to be financial gain, although I am trying to tell him there could be...