I totally get where you guys are coming from. I'd want that too. I can buy 5 Tesla cars and only have to pay once for the package. Saves me loads of money. But that's lots of money Tesla doesn't get to make. Look at it from their point of view. They're losing money on the deal. Repeat buyer numbers are huge for Tesla. In their eyes you're going to be buying another Tesla anyway. And there's a chance that you'll want that capability and will pay for it again (many do). If not, there's another chance that you'll miss the features and start a subscription. More money for them.
If I buy 5 Tesla cars over the years, and only pay for the FSD package once, Tesla made some amount on me (probably early days $6K) and that's it. If I never buy FSD again, they still made the same amount on me - $6K. But, if there is any chance that someone will pick up the FSD package again on a subsequent car purchase, that's additional revenue that wouldn't have happened otherwise.
I know, I know - "But if they allow the transfer, I'd definitely buy another Tesla again. Without that, I won't be buying another Tesla car. It fosters brand loyalty." The company is looking at the numbers right now and brand loyalty for Tesla is still very high, even without offering a transfer feature. So right now it doesn't make sense financially for them to do this. If brand loyalty and market conditions shift negative enough in the future, Tesla will likely pivot their policies to encourage sales. It's how the free market works.
When you see Ford have a huge sale on trucks, it's in response to market conditions. People started buying other brands, or inflation curbed spending from consumers. Ford isn't just going to have a huge sale on trucks when their truck sales are doing very well.
Again, I get it. I totally do. You just need to look at it from the seller's point of view.