The main scenario I can envision is backpacking long distances. Even then, I think it is really just an individual's choice. I believe most people will carry whatever size blade they are comfortable with and won't be hassled by authorities. This harkens to the old question; "if you could carry only one knife, what would it be?". I think most folks would want a larger blade a.k.a. survival knife when they are in a wilderness setting.