Here is a scenario.
You are at the gate with your Cat C firm business ticket in your hand. Waiting fo board. Unknown to you, economy is way over booked. So after the ground staff up grade as many business class into first. (Not you. Your ticket is business class). They then upgrade as many economy into business. Now all 3 classes are full.
You hear a PA. “Would Captain Jayto please come and see the gate staff”. You go and find out what’s going on. You are told “ sorry Captain. Aircraft is full. But don’t worry we have spoken to the operating Captain and he is happy to accept you in the
JS”
You don’t think that will happen?
totally unacceptable.