"Well yes, otherwise what's the point? It's like my hat and robes. If I didn't wear them, how would people know I was a wizard? And I worry about everything," he goes on. "It saves time."
"But what do they do when something awful happens?" Rincewind has only known one librarian and he naturally has a rather skewed idea of the profession as a whole as a result.
'Twas probably for the best. They didn't want them lurking about giving them a bad name. :D