G bodies were already dated by the mid 80s, which was when they were supposed to be discontinued as GM had planed. Because of problems and delays with their replacement, the W body, GM squeezed a few more years out of the G body line. As had been posted before, the 80s Gbodies are less well made than the 70s G bodies with the downsizing and deletion of structural bracing to cut costs, resulting in a weaker body and frame structure.
As for the history of hotrodding, it got its start from rum running moonshine to be faster than the cop cars chasing you. Most of the original NASCAR racers were rum runners as their main job. Hotroding did not start from returning soldiers trying to make their old cars faster, though some surely did. Most were concerned with starting a career and a family and forgetting the horrors they saw.
I try not get attached to brand loyalty myself, but I do like old machines regardless if they are outdated. But I do dislike the modern trend of giving up control for comforts and even HP, modern cars are just too nanny. Plus there is nothing simple about modern engines, lots of failure points to shift though.