Once Tesla is over "production hell" for the Model 3, we'll see a rapid increase of new Tesla owners using the superchargers - which will continue to accelerate over the next year. Even though FUSC (Free Unlimited Supercharging) is not included with the Model 3's, we should expect to see increasing utilization of the superchargers - and it will likely be difficult for Tesla to expand quickly enough to avoid having some superchargers getting swamped.
Continuing to add more supercharger locations and chargers at existing location is one part of the solution.
The other is more effective use of the superchargers - and this is where Tesla could do so much more than threatening to charge idle parking fees.
They know where the cars are located - they know which cars are charging - and should even be able to tell if a car is in a charging spot - and not connected (with the possible exception of chargers located inside buildings). For cars with AP2 - they even have cameras scanning the area when the cars are in the vicinity of the chargers.
They have a lot of information, and even without any attendants at the supercharger locations, they could use that data to implement better management and utilization of the superchargers.
Note that Tesla hasn't provided any official document on the supercharger usage policy. The Purchase Agreement, which is likely the only legally binding agreement doesn't provide any information on supercharger usage.
So Tesla could make software changes to help provide better supercharger utilization and back that up with a policy stating how the superchargers are and are not to be used - such as owners abusing their supercharger privileges could have that feature disabled (for a penalty period) - and their cars could even be instructed not to allow them to even pull into a supercharger space.
While the OP's concerns are valid - and are hopefully only impacting a small number of Tesla owners today, Tesla will likely have to do more than continuing to add more chargers, if they are going to prevent this issue from becoming more widespread and start impacting sales.
Continuing to add more supercharger locations and chargers at existing location is one part of the solution.
The other is more effective use of the superchargers - and this is where Tesla could do so much more than threatening to charge idle parking fees.
They know where the cars are located - they know which cars are charging - and should even be able to tell if a car is in a charging spot - and not connected (with the possible exception of chargers located inside buildings). For cars with AP2 - they even have cameras scanning the area when the cars are in the vicinity of the chargers.
They have a lot of information, and even without any attendants at the supercharger locations, they could use that data to implement better management and utilization of the superchargers.
Note that Tesla hasn't provided any official document on the supercharger usage policy. The Purchase Agreement, which is likely the only legally binding agreement doesn't provide any information on supercharger usage.
So Tesla could make software changes to help provide better supercharger utilization and back that up with a policy stating how the superchargers are and are not to be used - such as owners abusing their supercharger privileges could have that feature disabled (for a penalty period) - and their cars could even be instructed not to allow them to even pull into a supercharger space.
While the OP's concerns are valid - and are hopefully only impacting a small number of Tesla owners today, Tesla will likely have to do more than continuing to add more chargers, if they are going to prevent this issue from becoming more widespread and start impacting sales.