You are not correct. There are several forum posts complaining about this issue. One of which is linked below.
You can disable it on your profile, but to switch back and forth you have to stop the car, place it in park, switch to FSD, accept the agreements, re-apply all your personal settings for traffic lights and such. At this point, the double or single pull activation greys out and you are stuck with single pull, all or nothing FSD. When the car screws up and you don’t want FSD anymore, you must again navigate to the autopilot menu and disable it.
Or, like me, you can do this once in a safe location, save a second profile for FSD and switch immediately with two clicks from memory.
https://teslamotorsclub.com/tmc/threads/fsd-12-5-4-no-longer-allows-double-click-to-start.334535/
It’s the Tragedy of the Commons defense
https://en.m.wikipedia.org/wiki/Tragedy_of_the_commons