I think most people that are all for no power tools doing trail work have never really done any trail work themselves.
Earlier this year while I worked in Southern California where you have allot of brush we had a full crew of about 20 people with 4 brush saws running all day every day and in 8 days we got 5 miles of trail cleared which was considered a major achievement. With hand tools we probably would have been lucky to get 2 miles.
