I usually take it to mean design choices, not construction quality. Houses in FL today are designed to be tightly sealed so as to keep the heat out and the AC

I usually take it to mean design choices, not construction quality. Houses in FL today are designed to be tightly sealed so as to keep the heat out and the AC in. Houses from the 60's and 70's were designed to allow the windows to be opened and you get a nice cool airflow, even on hot days. I, personally, think this lack of openness in housing construction tends to keep people from interacting much with their neighbors. If your windows are open, people are more comfortable coming over and knocking on the door to say hello.