There is no doubt family dynamics & finances have been changing drastically the past many decades. With living expenses rising dramatically (the three biggest being housing, health care and automobiles) and incomes not keeping pace, families are really getting squeezed. The result - rising numbers of dual income households.
From 1950-2003, women in the workplace increased over 50%. As the trend continues to grow, it whittles away at leisure time, because it concentrates many of the day-to-day chores to the weekends - prime camping time! Don't get me wrong, I'm not saying women should, or shouldn't work, I'm just pointing out some of the factors that could result in less leisure activities. Then again, I could be way off in left field.