Could Tesla offer a fully self driving hardware Model S after only four years unless they had the most rapidly evolving vehicle in the history of the automobile! If you did not see that coming, you have not been following Tesla.
Even Elon has thanked folks many times for paying the huge price as early adopters. It has not been a secret you were buying something that would quickly be surpassed.
Innovation as a Battering Ram to beat the S*** out of the competition
In my opinion trying to build an entirely new car company and to keep it from going under, you must out innovate your competition. To do that requires the constant innovation we have been seeing. My feeling is that Tesla will need to continue that innovation. They need to focus on things like interior and exterior build quality to equal the existing nonUS manufacturers. I would say the build quality they have now is superior to most American cars I have ever seen, but does not match the best Europeans or the very best of Asia. It was funny the first time I sat inside a Tesla, the power, handling, and exterior were all awesome. The interior that vaguely reminded me of an average American car, but a little cleaner without the buttons. They have come a very long way, but have some way to go on that front. The seats in the Model X are an example of innovation we must constantly see, they look so much better than the S seats. They need to constantly improve in order to surpass brand x and convince more people to buy.
Hardware Retrofit Drains Resources from Innovations
Focussing resources on retrofits would drain limited resources from the enhancements we all want to see. As someone who works in software development, you're always balancing fixing issues with the current version while trying to develop new features. Too much work on current versions means no big enhancements or new versions. Would you be happier if it took 5 years to come out with autopilot v1 and 10 years for autopilot v2? Probably not.
Retrofit has a Potential for Immense Liability
In my opinion with US liability laws they are going way out on a limb compared to any car company that has ever existed implementing autopilot so rapidly to begin with. Trying to retrofit things like the self driving features or enhancements to those features is something that could easily kill Tesla if there were safety problems with those retrofits and all the differences they have in the prior versions. Look at what happened to Samsung or Boeing and the billions their battery issues cost them. My feeling is that the safety issues, complications, and amount of testing required of an automobile is many times that of a the most advanced phones ever created. Making updates to one common new version is straightforward. Multiplying the engineering, testing and different updates to the little differences between all the prior versions could bring innovations and updates to a halt.
Market Too Small to Justify
Probably 10% of folks are willing to spend the $5k or $10k at a time it would take for some of these updates, like autopilot upgrades, new seats, new bumpers etc. Is that enough of a market for Tesla to focus resources with all their other priorities they currently have, probably not. When it gets to be a much larger company, retrofits might be feasible, no doubt they are moving too fast and too lean to worry about that at the moment.
Don't wear yourself out trying to keep up with the Joneses
You are driving a car that probably 80% of Americans cannot afford to own, with many performance and convenience features that have never existed in history. Congratulations on your immense success in life, be happy with enjoy what you have now. You don't have to have the very newest and best every moment. You can be happy driving around your old and outdated P90D Tesla for a few more years even if it only has Autopilot v1. If you want to have something that evolves slowly and is very similar to the model from ten years ago, buy a Mercedes...
Look forward to that new Tesla you will no doubt buy in a few years based on the constant innovation...
May the circle of Tesla buying and whining continue...