What is the problem with people being able to make a call to cancel?

Recently I’ve noticed that people can’t seem to pick up a phone to cancel plans and then they think that a lame excuse should suffice. I was stressed, I got busy and forgot, I meant to call! They all sound like excuses you give a school teacher.
Sorry teach, but my dog ate my phone (or in some cases, phones). Once in a blue moon but most of the time?
Its no wonder that doctors offices charge you for missed appointments.
Do you forget to call? Short of not owning any phones. What is your excuse for not calling friends or family for not showing up after you said you would be there?