The problem is short cables - designed for a specific location of the charging port on Tesla cars - in the left rear corner.
If a vehicle has a charging port in a different location than the left rear (when parking backwards) or the right front (when parking forward), then it will very likely block some of the stalls/require an unusual parking approach. Tesla explains to not use the station if the car can't fit a stall.
"Does the Supercharger cable reach all EVs?
Certain Supercharger site layouts may not be suitable for some cars. Please do not obstruct other cars by parking over the lines if the cable cannot comfortably reach your car."
In the latest video shared by Bjørn Nyland, we can see an interesting example of what happens when one would like to charge a BMW iX (charging port in the right rear corner) at a Tesla Supercharging station.
As it turns out, the iX blocks some of the stalls at either of two layouts - the standard parking layout and the drive-thru layout.
Bjørn Nyland tries several times to minimize the issue, but it does not seem that the issue can be solved through learning how to park. The video was recorded at an almost empty station in the middle of a day, but at a time of normal traffic, the issue with non-geometrically compatible EVs will be much bigger.
This single issue, above everything else, is big enough to prevent Tesla from fully capitalizing from its charging network.
It's difficult to estimate, but potentially half of all models and a very substantial share of the electric car fleet will not be able to easily use the stations.
So what is the answer? If Tesla would like to offer charging for all electric models, then stations would have to be redesigned. Who knows, maybe there is some new type of station in the works already?
Actually, the list of potential improvements is long - from charging cable length, through trailer-friendly stalls and roofs, but all of those changes increase costs, so it's not an easy decision.