Tesla has been doing it for years with their 6K$ autopilot.
Well yes, and no. The computer is not just for FSD, it's for a lot of other things. You pay for the development of an extra software package. Think of it as your home computer. When you buy it with a decent operating system, or with Windows (Sorry, couldn't resist) you can do basic stuff like browsing and email. But if you want to use the computer for, let's say, flying a simulator you'll have to pay for the software. I think $6k is a bit steep for what you get but they can ask what they want and as long as it works, it works.
In this case it's more than just software; it's disabled hardware. Tesla used that to bring the price of the M3 SR down below an incentive threshold, but when that went south they changed their ways. In this case, they give you a 15.6kWh battery but really it's a 17.1kWh battery and for a price you get the extra 1.5kWh. The charger is a 6kW model but you get 3kW and for a price, you get the full 6kW.
This brings up a nice point for the buyers; If a company advances in technology, and you buy that technology, you'd expect to be able to use that technology. But now the company sells you the new tech, but allows you to use it like it's old tech until you pay extra. Would you buy the bike for a higher price if all the premium features were enabled? And, if these features are enabled, are they enabled for the bike retaining a resale value or only for the owner, losing the features when selling the bike?
IMHO, Zero is doing nothing wrong business wise but it feels wrong. You buy it, you use it. All of it. And if it costs more, it costs more.