So I have to tip a pizza guy because society says tip a pizza guy? If your total at McDonald's is $7.37, why not give the kid a ten and call it even?
And $1.44 is a good tip on a $23 meal? That's a hair over a 5% tip. Also, if calculating and counting out a single, a quarter, a dime, a nickel, and four pennies is really tough on this kid, maybe handling money isn't the right job for him.
So you tip not out of the goodness of your heart, or out of thanks for service, but because you're uncomfortable with change in your pocket?