Interesting question.
I saw that in England, you may own and drive a WW2 tank on the streets, provided it is modified so as not to shred the roads, has proper lights and, of course, the weaponry does not work. From what I can tell, even the biggest SUV could not hurt one of those nor a semi-truck. You’ve the right to drive one of those so long as you use due care.
The same with an SUV. Provided you do not go blasting recklessly about, use due care when around people with more fragile cars, your responsibility towards others would be met. If they slam into you and experience more injuries because they drive an economic small car, then your responsibilities are still kept.
Like, if you were driving a WW2 tank, that can only get up to around 40 mph and someone plowed into your heavily armored side at 50. Certainly, the results would be like hitting a brick wall, with little injury to your vehicle, but it would be their fault.
Now, while the economic factor is something to consider, concerning those who can afford it buying a safer vehicle while those less off have to drive beer cans with wheels, well that doesn’t actually seem to fit into the realm of personal responsibility. That would fall into the vehicle manufacturers lap.
People buy what they can afford and people take their own responsibilities for their actions. Like, bikers getting the helmet law repealed so they can feel their hair blow in the breeze. Well, now they’ve begun to scatter their few brains all over the pavement in accidents also.
They had the option to wear helmets and chose not to. So, any severe head injuries they incur even if in an accident not caused by them, that could have been prevented by a helmet then becomes their own fault.
That is like the extreme sports nuts. No one forced them to jump off of that mountain wearing a parachute and if they slammed into the rock face on the way down and broke both legs, then that is their responsibility, not that of the mountain guide nor the parachute maker.
It is possible to make all types of safer cars, in order to even out the field, so to speak, but so long as the automobile industry is basically profit oriented, that will not happen. If it does, then a lot of people will not be able to afford the resulting cars. As it stands today, the car industry could make safer cars, take a little less profit to make them affordable but the decision makers are not willing to do so.
So, basically, they assume responsibility for producing a vehicle that they know will not stand up to an impact from something like a big SUV. Unfortunately, they don’t care and it is still buyer beware.
Now, if we could ever force through a law requiring all car makers and dealers to tell every potential buyer the absolute truth about any selected vehical, that would help, but it’s not likely to ever happen.