I understand what you're saying. Why retrofit a car before the person wants to activate FSD? Or, really, why retrofit any car if they never write software that needs it (the most likely scenario)? But you're looking at this from TSLA's perspective, not the consumer's.
The problem here, from the consumer standpoint, is that I paid for a car with the hardware capable of FSD (I am happy to post the image again!). If 2.5 is needed, then my car does not have the hardware capable of FSD. The terms of my purchase were not that they would add the hardware capable when I wanted the software. It already HAD it.
(They don't have to provide tires only if I want to drive the car.)
Even if it makes sense for Tesla not to want to proactively replace the hardware for people who have not yet paid for FSD enabling (it is a cost, of course Tesla wouldn't want to do it!), it is a contractual obligation set independent of whether or not an owner bought the FSD option.
I'm talking about contracts, not what is best from Tesla's perspective. I frankly don't care what is best from Tesla's perspective.