Because IP addresses feel private. Even though you send one with every packet. Even though the extra one sent by webrtc is the one behind your NAT, and probably just 192.168.[0,1].
They can actually be private. What if you set up a proxy or a VPN with the express purpose of masking your real IP address, and then WebRTC barfs it out on demand anyway?
Again, WebRTC does not "barf" out your real IP in a VPN situation -- it barfs out the VPN's internal IP, which is meaningless to anyone except for the VPN's operator (and they have that data anyway).
Your actual, ISP-assigned IP remains hidden to any site you visit.
I thought it would provide every IP address held by the system, which would include both the internal VPN IP address and your actual ISP-provided IP address.
