People with long legs relative to their torsos often have lots more seat-post showing than someone on the same size bike who has shorter legs and the same length torso. People who like a more performance-oriented set-up will often have lower stem-height, too. My saddle is generally just a hair taller than my handlebars, because I have relatively short legs. If I didn't like to ride with relatively aggressive posture my handlebars would be somewhat higher and more even with my handlebars.