All true.
The way you frame it however you make it sound like there is some shadiness going on.
In reality the FSD package is the best ADAS system by far and is priced as such.
What you also fail to mention is that the $10,000 price tag gives you a free call option on the progress of Autonomy.
If FSD package does end up being pretty much L4 by the time you sell the car, be that v10, v11, v12 etc it will attract an enormous premium second hand as a purchaser would need to either forgo this capability on their Tesla or pay the brand new retail price of $15k,$20k,$30k (whatever it ends up being) or subscribe at $300+ per month. Therefore, cars with FSD capability will retain a higher residual value than those who don't. This difference in second sale price may encompass part, all of, or exceed the original purchase price of FSD. The $10k purchase gives you the call option to capture this price difference of Non-FSD second-hand sale price and FSD-enabled second-hand sale price.
People who purchased this call option in 2016,2017,2018,2019 have more or less lost as its unlikely that they will see residual value from the FSD purchase nor be able to use L4 functionality. However, that doesn't mean that everyone buying it in 2020,2021 and beyond will necessarily end up in the same fate. Reasoning by analogy or past performance is a fools errand. If you look at the progress being made right now in deep learning and machine vision, its becoming increasingly more likely that at some point in the future FSD will have L4 capability. When this happens is anyone's guess but it does at least appear the path Tesla are on is the winning approach.