In my area, not showing up for an appointment is a pretty typical way for a farrier to tell you he no longer wants your business. Like wild_spot, I live in an area where demand exceeds supply.
I got off to a rough start with the farrier I've now had for 2 years. Bit of a diva, and pretty stiff pricing. HOWEVER, incredibly reliable - usually he's early, and has never missed or been late for an appointment. He also does a great job with my horses; completely fixed an overreaching problem that one horse had. So I've come to be very grateful for him; and don't mind stroking the checks.
Since I have to schedule farrier appts around my office job schedule; someone who wasn't reliable and on time would be very hard to work with.