I am totally bored out of my mind so I thought I would enter this minefield. It happens all the time on BOTH sides. Many times I would love to see someone and have a whole 60 minutes to get to you, play for the HHR and then get back to work. Its called Lunch. Guess what is super annoying? Sitting in the lot waiting and then leaving. Then my phone getting blown up about how your now ready 30 minutes after we were supposed to start (this is a generality not personally to the OP). Or how about sitting in front of a House for 20 minutes and then I just leave. Who actually flaked? What about emergencies? They happen or as I like to call it Life happens. If your son or daughter has an issue at school THAT is probably the most important thing on your mind and your not going to care about me sitting in a car till your family is taken care of.
THE DIFFERENCE is the habituality. That's why you have a ladies section to talk about stuff. Is the person habitually late. Your best bet is to share information. If someone is habitual you are taking the risk. But is someone has a bad day, texts to apologize, then so be it.
Again Life happens to everyone.