Indeed, but considering some of the comments from other parents on this thread--and accounting for my own experience--spending time with one's children, just being present in the world together, exploring and fostering experiential learning, is not as simple as it would at first appear. Parents' lives are beset by demands and obligations outside those of parenting and managing a household, so it can be incredibly difficult to balance these disparate tasks and still make time to be present in the lives of their children on a timetable that does not begin to negatively impact the children's development.
Quality time is important and possibly one of the scarcest commodities in our economy. The importance of experiential learning (eg, dining together at the table), wherein a child learns about the world firsthand, including how to comport oneself in various situations, cannot be understated.
That can't be taken for granted anymore.