I usually don't get all that pissy about doctors running late. However, there was one time I was really irritated.
I took my wife to the doctor for an appointment. She got the first appointment of the day. We were there 45 minutes early. We waited more than 30 minutes past when the appointment was supposed to start. While we were waiting there, the doctor came in through the waiting room.
It's one thing to be running late because of the normal day to day delays that happen in a medical practice, but if you're actually just running late getting to work, you should call and have your staff let the patients know.
My first day at my duty station I was 10 min early to work and a staff sergeant told me if I wasn't 15 min early I'm already 5 min late...good words to live by
The military. It's ingrained in you from like day one that if you're not 15 minutes early to everything, you're late. It's also why you'll hear folks from the military talking about standing in formation waiting for 3 hours before the Colonel/Captain even shows up. By the time the order gets from the Colonel to the Private, everyone in between has padded the arrival time by an extra 15 minutes.
You don't clock in and out in the military, so sure, fine. And for job interviews, it looks good to employers. But beyond that, I'm in the "if you want me here early, you need to pay me for that time" club.