[Sloth]

The restaurant want the customer to get good service and be inclined to return, but the manager cannot possibly monitor the staff 100% of the time, so they "outsource" the job to the customers, who gives feedback based on the service they receive... So they aren't passing off the cost, they are simply passing off the judgement of how much each server deserves.

Eating in a restaurant should not involve acquiring job responsibilities. If they want me to do personnel evaluations for them, they need to pay me.

Just pay the servers adequately, raise the prices and leave me be.

[Truthsearcher]

They do pay you, with better service.

I guarantee you in a system where you don't tip the service will be worse.