Nobody likes to wait, I get that. Some people handle it better than others. I’m not one of them. It enraged me when friends arrived hours late. Ten minutes tardy, no big deal. Three hours late, and the least you can do is call and advise three solid hours are now available to do something else.
When somebody can’t be bothered to call, their silence sends a message. That message is, “Your time is worthless. Mine is precious because I am important, unlike you. The best use of your time is waiting for me.”
I phone when I’m more than ten minutes late which happens more often than it should because I cut it as close as possible. This is more than a little hypocritical because, when I cut it close, I risk being late. For sure, I’m never early because being too early usually entails waiting, too.