When I drive my work van I use a throttle body, when I drive my car I use a carburettor. From my point of view as a user, I'm just driving a vehicle. The point is that users see a holistic system and neither know nor care about the underlying implementation details.

  > The point is that users see a holistic system and neither know nor care about the underlying implementation details.

Yes, this is my point too. End users are not "using IPv6" even if that protocol is in use to transfer their data.