[throwaway313313]

Because the goal of a marketing manager is to extract more money from you not less, by creating an accepted practice of disabling functionality to optimize the money you are willing to commit to actually pay over the lifetime of owning the car.

The point is to find the most innocuous thing that you would accept at time of purchase and then make the majority of customers pay for that more often and longer than anybody at the time of purchase thinks about.

It's similar to the marketing for payday loans. People are not entirely rational actors.

If you could make double the normal sales price of the car in revenue, and the car stops working if the customer ceases to pay, then if you don't mind the occasional customer service public meltdown on social media, then as a car manufacturer you are welcome to scheme away.

As a smarter than average customer, you are wise to the scam, and hope that the scheming of the car companies is not effective on the general public.

Also subscriptions are awesome for car manufacturers for accelerating planned obsolescence. Why should there be any resale value to your car anyway, if they could figure out a way to either 1) make the new owner pay for the car again in subscriptions or 2) make your car near worthless after you initially own it, then from their perspective this is the most brilliant thing they have ever thought of! ;)