"and in the unlikely (but possible) event that the hanging cable snaps, you won't lose the wheel into the road and hurt other drivers with it."
Very good point about the hanger snapping and losing the spare. It's happened more than you might think to trucks, mini-vans, SUV's etc.
Corrosion and wear can cause that to happen and some fatal highway accidents have resulted.
Our trucks PROBABLY have a new-design spare-tire carrier that incorporates a secondary latching mechanism that'll retain the spare if the hanger cable breaks.
They were supposed to be on all GM vehicles (with hanging spare tire) beginning about 1-1/2 years ago.
I've been intending to drop my spare and look for that fail-safe hanger but I just haven't had time since I got my truck.
You shoulda been with me a few years ago on I-85 when a rear tire and wheel on a big 'ol 70's model Ford wagon came off at about 70 MPH in the lane next to me. Wow...
If I told you what happened, you would never believe it.
I didn't believe myself it as it was happening right in front of me...
Nobody was hurt though.