Superchargers priority are first to long distance travelers who have no other options. Next to local people, also with no other options, Then for commercial users and owners with only 110V availability, and need a quicker charge, last to people nearby that have perfectly good 240V charging stations in their nearby garages but wish to use the Superchargers because they are free.
If there are long lines, and travelers cannot get to a charger in order to get home, or to their next Supercharger on their route, it would be nice if a local person would unplug and come back at another time, when the line was gone.
No Tesla owner should ever be excluded from access to an empty charging stall, however, just as a glutton should not wolf down the last piece of food when a starving man is in need, common sense should be a staple in the Tesla owners personality.