Entitled people, at any age, income, region, etc..., can be d@$ks.
I charge at home, but if I were given free supercharging, and it was convenient for me to rely on that, then that's what I would do. And I can understand how someone given this, before the huge influx of model 3s, would feel possessive and entitled. I don't agree, and that person is a d@&k, but I understand the psychology there.
Though, the more these things happen, the less convenient it will be to SC, and the more people will begin to charge at home.
There are simple solutions others here have mentioned. Would be easy for Tesla to set up an electronic queuing system.
Also, if chargers were set up more like gas stations, where you have to get in line and then pull forward to go past the pump/charger, there would be a natural que. the problem with SC is when they are crowded, there is no natural way for everyone to agree on a que, and it is frequently not obvious visually. Leads to arguments when not everyone is paying attention, and when some decide they are more important than others in the world.
D@&ks gonna be d@&ks.