How many times does this come up a month?
I worked in restaurants for a long time, so i take this personally.
*WARNING* I am about to say not very nice things, Take it as a difference of opinion, not a personal attack. Also, I'm on painkillers due to my back seizing up 2 days ago.
Look, 20% is standard, absolute minimum, for average service. If you can't tip, stay home in the trailer park where you belong
If you think that "all they have to do on a takeout order is hand you a bag of food", who do you think takes the order and packs it up? We used to have a major problem with Waiters never taking to go orders at a few places that I worked at, because some Douche would tip a quarter on a 30 dollar order, taking time away from customers that were paying for service.. Here's an idea, let me dump your food into a bag, instead of carefully putting it into containers, and seperating hot and cold items, including take out silverware, appropriate sauces/dressings. 20% is a little much for take out, but you should leave something.
If you're in a bar, it's $1 a drink. If you think that's crazy, then die of thirst.
As far as subtracting things off a bill, I can only hope that you're joking.
There are 2 things to consider; The kitchen makes the food, not your waitstaff. Too many people punish the waiter for bad food. That is a matter that the manager should take up with the kitchen.
and yes, Waitstaff is paid below minimum wage; 2.15 an hour, my friend. On their feet for 6 to 8 hours a day, no breaks, Literally running for 8 hours, no benefits, and now they're taxed on tips.
It's your Karma, not mine.