My radar failed/went out of alignment. I had no cruise (or autopilot, understandably) while I waited for my service appointment.
There's no legitimate reason that the car can't default to old-fashioned 70's era cruise control if the radar goes wonky.
If liability is a big concern, pop up a warning dialog on the center console and make me click "I agree I am too stupid to breed if I forget the traffic-aware feature is deactivated and hit someone." I'm a big boy; I can handle it. I've been driving cars with boring old regular cruise for decades and never rear-ended anyone.