what about if the meat has been left out all night or has freezer burn

Take the human out of the equation in a lot of the process, and things like this will occur less. There will not be a reason to keep the meat out all night. Freezer burn can be drastically reduced by better processes. Humans screw up processes much more.

What about expiration dates on stock?

This must be one of the simplest things for a automated system to take care of. If the expiry date is in the system, it will know exactly when it is expired.

The ketchup is runny or smell off?

Test viscosity, bacteria / microorganism presence.

What if the food isn't seasoned correctly?

If it is empirical, a robot will do it better.

Well done steaks? Medium rare? Medium well? How does a machine know?

Just as humans do - by testing resistance. Only a machine will be far more precise.

There will always be humans in the mix, for supervision, for quality control, and it in several instances, they will even be much cheaper. Their flexibility, adaptability, and learning curve means humans in many instances will provide far more utility than machines.

But the number of humans needed will decrease over time.