There is consistent proximity throughout the logotype. The negative space forming the "N" makes sense with the name because looking at the logotype engages the audience when locating the "N". I also think the logotype font works well bold.
Southwest Airlines' motto in the is said to have been "sex sells seats," and flight attendants were dressed to fit the bill. Widely known as "The Love Airline," Southwest resisted hiring males until after losing a class action lawsuit in