Saltaire,
I 'm sure they're grateful and all, but I will give you an example of one of them's reason for unhappyness.......Imagine you're in HKG living it up with CX .......then someone from your family (mother,father , sister etc....) falls ill with something like cancer or one of your close friends and you want to be there for your family but you cant unless you have vacation or quit.
Then you put things in perspective.......even if it did get you a command on the freighter