Why the Swing Axle Rear Suspension Went out of Favor
 

While I didn't read the link, the real killer was Ralph Nadar - "Safety at any speed"

Killed the Corvair. Almost killed VW. Don't forget MB ran swing axles into the late 1960s in their S class cars too. Beetles soldiered on for another 20 or more years in various 3rd world countries.

The link goes to about a 4 minute video clip of VW (and some others, including one 911) spins and rollovers at the Nurburgring, looks like ca.1970 or so. About 2 mins in is a particularly good one where a V-dub, apparently tiring of all this nonsense, spits the driver out the door onto the ground.