If there is no power than chances see there is limited steering as well. Probably safer to have motionlessn 2-ton rock rather than a 2-ton ballistic missile.
Power steering might be off, but that doesn't mean steering is limited.
A motionless 2-ton rock in the middle of a busy interstate because of a power blip is a terrible idea. And again, how hard exactly should the system brake? Pick a value between 0% braking and 100% braking that brakes maximally without locking up the brakes.
A 2-ton brick spinning down a busy interstate because the brakes locked up is arguably even worse than a motionless one.
