...Remember, many times the wait staff's hourly wage is minimal as they are expected to make their money on tips. IOW, the employers do not consider it a bonus but part of the wages.
So the restaurant - could raise its' price - to give the waitresses a wage of about $10 an hour.
But it they do that - now you have to pay tax on the increase of your bill!
For a $700 + order - I agree that a tip should have been given.