You don't design a feature that invites misuse and then use instructions to try to prevent that misuse. That's irresponsible, bad engineering.
The heirachy of hazard control [1] in fact puts administrative controls at the 2nd-to-bottom, just above personal protective equipment. Elimination, substitution and engineering controls all fall above it.
Guards on the trucks to stop cars going under are an engineering control and also perhaps a substituion - you go from decapitation to driving into a wall instead. It's better than no guards and just expecting drivers to be alert - that's administration - but it's worse than elimination which is what you need if you provide a system where the driver is encouraged to be inattentive.
User alertness is a very fucking difficult problem to solve and an extremely unreliable hazard control. Never rely on it, ever. That's what they're doing here and it was only a matter of time that this happened. It's irresponsible engineering.
edit: My source for the above: I work in rail. We battle with driver inattention constantly because like autopilot, you don't steer but you do have to be in control. I could write novels on the battles we've gone through just to keep drivers paying attention.
[1]: https://en.wikipedia.org/wiki/Hierarchy_of_hazard_control