Actually, they have an ugly steel bumper that looks similar to a chunk of guardrail, with a molded flexible plastic cover hiding it.
Right you are. I guess my beef is with the plastic that covers it. Hit something going just a few mph and that plastic gets crunched and cracked, necessitating big money repairs.
On the other hand, I remember those old steel bumpers to be pretty much indestructible. (But nostalgia might be coloring those old memories.)