One reason is that those who like to work with their mind (so to speak) with minimal physical activity are probably not the demographic that are also interested in a physically taxing job like agriculture.
that was a piece i was trying to illustrate in my question; passively though. many think farm/agro work is physical it is but I'd hedge that its more "mind" work than physical. from marketing strategies, being able to communicate, laugh, enjoy the space etc. Moreover now folks like myself in the space are seeking to develop awesome digital/and physical bartering systems. Thing is when one really works land your realize that you need the folks ( Plants, animals etc) to which (mainstream)MS excludes from the space.