In my opinion, it is always inconsiderate to leave a Tesla in a Supercharger stall for longer than the time it takes to complete the charging session, particularly considering that the Tesla app will notify you when the charging session is complete.
There clearly are some Tesla owners that need to be more considerate of others who need to charge. And if that means public shaming (posting photos, including license plates, of Tesla vehicles that are done charging but are still occupying a stall) I don't have a problem with that. Peer pressure can be an effective way to change behavior.
And if someone catches me abusing a Supercharger stall please don't hesitate to call me out on it!
Tesla is not spending money building Superchargers for use as long term parking. They are for charging our cars, only.