The way I read it, the OP was talking about people needing to drive micro-cars (e.g., ones that can only hold 2 people, like the micro-cars that are only sold in Japan). Those cars would fare very poorly in a crash against just about any typical car (let alone SUV) on an American road.
The argument I was addressing was, if its really an arms race, then no way we would go from the 4800lb Ford Thunderbird to the 2600lb Ford Focus in a generation.
Folks have by and large opted out of the arms race. For better and for worse.
The 4800lb Thunderbird buyers aren't buying cars; they're buying SUVs and crossovers these days.
Ah now I see they're renaming it the 'Active'. My mistake.
However, there's still people buying cars, but usually they're foreign makes. The American carmakers have spent decades trying to prove to people that they suck at making cars and only put their effort into trucks/SUVs, and American car buyers are finally getting the message.
The Ford F150 wishes to disagree.