A debate, perhaps worth having. Meanwhile your server makes less than minimum wage because tips are expected to fill in the gap. A while back it was $2.13 an hour. Not giving him a tip is only going to ruin his day, not start a revolution. As of right now, the chicken dish cost $16 plus an unofficial but expected 15-20% tip. Do you have the roughly $20? if not, grab a few slices of pizza.
Edit: I don't tip 20% when I grab a coffee at Dunkin. Oh no. Maybe leave them the loose change.