I'm wondering if Tesla could change the way the setup these "parking" spaces. Right now they are setup like parking spaces and not like a refueling space. It would require more space, but if they setup more like a traditional refuelling island the ICE vehicles might not feel like they can park there. Almost all the photos I see of ICE's spaces are where the pedestal is at the back and the Tesla would back into the space for fuelling. The few sites that have the pedestal on an island at the front (out in the lot) of the space don't seem to be ICE'd as often. If they were pull through islands, it might be even better. Just a thought.
This begins to get at the real issue. The problem, in my opinion, is that superchargers should never have been PARKING SPACES. They should be electric "gas" stations. With "pumps" that you pull up to. Sure, you might sit and "park" for an hour or so, but, so what, it's a slow "gas" station.
It would take more real estate and therefore cost more but it would be obvious that this is not a parking lot for the non-educated/ignorant ICErs out there. They would see this thing, maybe pull up, discover it is not a gas station but an electric charging station, and have no reason to stick around a "pump".
The world has had 100 years of gas stations and everyone knows what they are, and the behavior around them is known by all and in our genes. Parking lots have been around for just as long and the behavior around THEM is also known by all and also in our genes. Problem is, parking lot behavior is very different than gas station behavior.
The big problem here is that Tesla is being cheap, kinda has to be, in locating Supercharger sites in busy parking lots where people, you know, PARK. It should be locating Supercharger sites somewhere else. I personally would be glad to walk a little further to the local greasy spoon if these ICEing situations were mostly eliminated because Superchargers were no longer located in parking lots. Not going to happen, I know.