In short (pun intended), Rybczynski thinks that architects tend to be introverted and insecure, and tall people usually aren't.
"Julia Morgan, another celebrated Bay Area architect, was only 5 feet tall. Raymond Hood, Ely Jacques Kahn, and Ralph Walker dominated New York high-rise architecture in the 1920s-Hood designed 30 Rock, Kahn was responsible for the wonderful 2 Park Avenue, and Walker produced the Art Deco tower at 1 Wall Street. They were so short they were popularly known as the "Three Little Napoleons of Architecture." (Napoleon was 5 feet 6½ inches.) "