Some of you seem to forget, medicine is not first come, first served. You come in with an appointment for an irritated hangnail. The guy after you comes in, no appointment ... a walk-in, with chest pains. Who do you think is going to be seen first, and who is going to have to wait? Medicine is a lot different than the food line at Burger King. A whole string of appointments, one after the other, may get delayed because one person came in earlier for an ear infection, and promptly proceeded to have shortness of breath and fell to the floor. That 15 minute ear infection appointment then turned into a 2 hour ordeal of EKG's, oxygen therapy, an IV, cardiac drug administration, monitoring, and coordination to transport to a hospital and a whole bunch of other stuff that never gets mentioned to you by the doctor when there is enough time for you to finally be seen. And you have the people who come in like clockwork for very minor things, then proceed to talk for hours about every niggly complaint they've had over the last 30 years, expecting you to fix them (when most of them have already fixed themselves, because they were non-issues in the first place). After a day of this, and being whined at and yelled at by the hangnail owner, the doc finally gets to go home at 9:00pm after having missed their kids 7:00pm school play (for the second time that week).
There is usually a very good reason why your appointment was delayed. They're not sitting in a back room playing cards, scheduling appointments they don't intend to keep, and laughing at you out there waiting. And you will never be told what the reason is because of HIPAA privacy laws. If you ask, you will get a coy non-answer, just like if you ask the bank fraud department how they knew your credit card was compromised. You don't think the doctor has a good explanation of why they were late? That's because they aren't allowed, by law, to give you that explanation.
I remember a doctor friend telling me how people would come into the ER because they had a tick on their leg. He'd pull it off with his fingers. Then they'd yell at him for charging so much money for a "stupid tick" (it wasn't the doc charging the money). They were clueless that the stupid thing in the encounter was not the tick. So what he started doing was pulling the tick off with a pair of hemostats instead, and then he'd set the tick in a little medical-looking dish instead of flinging it into the trashcan. He'd pick up the dish, look at it with a magnifying glass, say "Hmmm", flip through the pages of some random book on the shelf, type some things into the computer "all work and no play makes jack a dull boy" - the morons were happy then.