Good Ol' Wikipedia has some very interesting insight on them. All makes sense. I realize they aren't considered the most reliable source of facts, but all of the following makes sense to this guy:

"In German the style is referred to as "Lesepfeife" or "reading pipe," presumably because the longer stem allowed an unimpeded view of one's book, and smoke doesn't form near the reader's eyes, allowing one to look down."

"Such pipes were very popular as an Oriental influence from the 17th century onwards in Europe. They remained most popular in Eastern Europe, as an emblem of the "Hussars," cavalry troops with roots in the Austro-Hungarian Empire, who went from Russia to France and England during the Napoleonic Wars and brought the pipes with them. It was even known as the "Hussar pipe" at the time. Engraved portraits exist of men smoking such an instrument. This long stem pipe type has its origins in the Ottoman Empire, geographically and historically."

"Churchwarden pipes were reputedly named after churchwardens, or night watchmen of churches in the time that churches never locked their doors. These "churchwardens" couldn't be expected to go all night without a smoke, so they had pipes that were made with exceptionally long stems so the smoke and the pipe wouldn't be in their line of sight as they kept watch. Churchwardens have experienced a surge in popularity in recent years, thanks in large part to Lord of the Rings film trilogy, wherein many of the characters smoke Churchwardens or other pipes of similar design."