As a Waiter who sells about $1,000 in food every 4 hours, I genuinely feel my tips are and should be a reflection of the service I provide, and that's okay.
And honestly, even if I give world class service, some people are going to tip what they tip regardless, and that's okay. It sucks getting 10% on a $200 check, and thinking I should have made $40 instead of $20, but it averages out. Some tables make up for it, and others don't.
In the end, I walk out of a shift with about $150 every $1,000 sold after I tip out $30 to my support staff. That's about $37 an hour. For an entry level job, I really can't complain about that. I'm generally making more hourly than majority of the guests I serve. I'm not gonna overly focus on bad tippers and let them ruin my mood/day. I feel bad for anyone that does. Working a serving job when you NEED to make X amount of money is terribly stressful, but it's not the best attitude to have when you let "Fuck this Asshole left me $10 on $100!" Ruin your whole night.