Wow, you drank a lot of the koolaid.
You're insane if you think '60s iron is better in a crash than today's cars.
So cars had different personalities just because they looked different? Tell me about the difference between a Malibu SS, 442, GTO, and GS? Apart from the grille and the engine they were the same car.
Muscle cars appreciate because of nostalgic baby boomers. I'm old enough to remember when these cars were new. If you used a '60s American car as a daily driver, it was spent by 75,000 miles. The interior would be worn out, engine would be burning oil, you'd already have been through four sets of tires and three sets of shocks, headliner and weather stripping would be coming off, u-joints would be ready to fail, the cars were mechanically and cosmetically junk by 75K. Muscle cars are rare now, because so many of them were retired as junkers by 1975.
Don't get me wrong, I get the nostalgia too, and I'm not immune to the sound of a big V8 burbling, or the feel of the torque. But realistically, by no relevant measure were these actually Good Cars.