I've heard it is called "flaking"--  people who say they will do something, and don't;  people who say they are going to show up, and do not.  From my experiences, it is very rare that anyone ever has a legitimate reason for this kind of behavior.  They simply have no concern for how their irresponsibility affects others.  While it is something I rarely experienced before, in recent years it has affected everything from everyday life to work to other business.  It has ranged from minor inconvenience to near-disaster.

I honestly do not understand this "trend."  Are people really so scatterbrained that they do not have the ability to follow through with whatever they say they will do, or do they simply enjoy creating chaos?  In nearly every instance that I've experienced personally, it's been a matter of brushing off the inconvenience to me as completely inconsequential.  However, the worst part of "flaking" is I've found regardless of how politely you may ask someone why they did not follow through with something, the response is always very negative.  When someone brushes you off, they become irate with you--  as if you had no business expecting them to keep their word.

In most cases, it's amounted to wasting time.  To borrow a line from the older generation, when you "hurry up and wait," and find the waiting has been for nothing, there were other things you could have or should have been doing with that time, rather than waiting for a no-show.  You put off other things you need to do in order to accommodate individuals who never bother to show up, and do not let you know they are not coming.  

As a freelancer, it's been more than annoying on the work-front, too.  There have been countless instances where individuals, who claim to be professionals, inform me they are sending work projects 'tomorrow,' "Monday morning,' or 'by the end of the week,' and leave me hanging.  I also encountered this habit with an in-person job.  A woman offered me a job;  I waited for her to show up.  When she never arrived, I left a number of messages on her phone which she never answered.  When she showed up a couple of weeks later, she said "I didn't answer your messages--" *shrug* "just because I didn't."  

I sometimes think if I become rich some day, I'll buy everyone a clock, a watch, and a calendar.  Somehow, though, I doubt if it would make any difference.  When people think other people's time is theirs to waste, there is not much chance they will change.