I think this is a legitimate question, but I think we need to give ourselves a little bit more background to other cars.
BMW's as of late have an electronic gear shift selector. Kinda like jag's or even prius's (which I have). There is no mechanical linkage between the transmission and the gear selector. Because of this, the transmission's gear (PRND) can be changed by other means, in this case, the power button. In my prius, you can shut the car off with it's power button and the car will automatically engage park when stopped. It's a nifty feature, saves a step and is something one can get used to. Not understanding the reasoning behind this can lead to the public becoming "ignorant and complacent."
However, with the cx5 (and many other cars), the gear shifter has an actual mechanical linkage and requires drivers to manually place the car in park when stopped to put the car into transmission lock, which is what keeps the car from rolling away. Leaving it in drive and shutting the engine off does not allow the transmission lock to be engaged.
It can definitely become a safety issue if one is not aware. But I cannot think of any other cars that have mechanical gear selectors where if you leave it in drive and turn the engine off, the car "sits like a rock". That statement confuses and worries me, in regards to the accord that was traded in.
