That's because while current owners got burned, when they needed a new car they didn't have much choices in the EV market. Furthermore, while they started selling beta features early, they did bring them out eventually, before other competitors. Then there are some people who got burned and traded-in immediately for the latest and greatest. Talk about the loyalty of being burned!
Now if in a couple more years with other major automakers mass-producing EV / autonomous vehicles (very likely as they are all taking it seriously, unlike recent years), this might change. I for one, would not get another Tesla if there are more choices in a couple of years.