Cars of the 60's are not sought after by only old men....the younger generations would LOVE to have them, too, but generally can't afford them. As I said...let's see who is fighting over a 1992 Taurus in 30 years.
Cars of the 60's didn't 'rot', rather, they were not built to withstand years of outdoor exposure as modern cars are. IMO, anyone who leaves a vehicle outdoors deserves to have a shitbox in 5 years. Imagine buying a $50,000 VMC and leaving it outdoors for 5 years. No different for a vehicle.
As I've said, there is no doubt systems have improved in the past 6 decades. They should improve - that's the natural progression of a healthy society. But cars have also degraded significantly...they are overly complex, full of shit designs and features, and nearly impossible to repair. Most of all, they contain computers which are the doorway to Hell.
A 1977 Volare? Really? You're gonna choose one of the worst years ever as the example? By 1973, it was a rapid downhill for all cars, no matter who made them.
As for safety....your showing that chart shows just why this country has gone soft. Do the Chinese care about safety? The Russians? The Pakis? Nope. They're getting tougher, we're getting softer. History has proven that is never a good outcome for the soft.