>>1185011To support underpaid food service workers because their employers are so fucking frugal they make Jews jealous.
Like, if an adult woman gets hired to be a waitress for $10 an hour, her employer would use legalese to his advantage and scam her by only paying her $5 per hour and she has to make the other $5 with tips.
tl;dr you pay tip because the owners of the restaurant you visited are scummy asswipes