Some people don't like to be without a passport for a month or two. They could need to do some last minute business travel or there might be a family emergency requiring foreign travel. Or some people just tend to foreign travel at least every month or two. If someone lives near the Canadian border or has a second home near the border, they might routinely take unanticipated/unscheduled day trips into Canada.

IIRC you can do a regular (nonemergency) renewal at a Passport Agency and get the passport by mail in about two weeks.