Casual hikers with no experience of Leave No Trace (environmentally conscious outdoor ethics) are more likely to have an impact on one single place. That's the main reason for the ridge runners.
Through-hikers live out there for five to seven months and so individually they have a higher impact in a years' time but they also are more likely to at least become more conscious of having less impact.
The message we are trying to get out is to be conscious of different points of view and people's different experience. Our overall position is we don't want anybody abusing a resource - that we would object to.