I was not aware. I make the same case with 85 as I did 65. Throw in a GPS and you could make the distinction.
Then in 10 years, someone, somewhere decides that 90 is acceptable on a specific road. Now all cars with limiters need to be modified. Want to be able to change it remotely? Now you add an attack vector. Throw in a GPS? Now you're asking for additional government monitoring that is mandatory and might be (will be) used for spying purposes.
You could design a GPS speed limiter that doesn't track location, TomTom's had an "overspeed" warning 10 years ago, it would go orange if you went over the speed limit and go red and make a bong noise if you went way over, My old boss used to drive fast so I saw that quite a lot (in the end I told him I wouldn't share a car with him if he didn't stick to the speed limit).
Nissan GT-R's have (at least in Japan, where it is as far as I know mandatory, not sure if they are removed in international sales) limiters that deactivate when they are on a white-listed race track.