OT
I am also very patient and understanding to waitresses and I tip very well which usually shocks a lot of them. I dont eat out often anymore but when I do, I try to give minimum tip of 25% when I can afford it. Ive also been know to give a waitress 50% or more just to make their day.
The reason?
I waited tables myself for a couple years and know how hard a job it is and know the type of people they run into. The cook is the one who cooks the food so I dont hold anything against them if it is a cooking mistake and I try not to complain or send something back for more fire unless it is really bad.
With that said, there was a couple times in 20 or so years where the waitress was rude and terrible just like you experienced. For those times, they get the minimum tip but the manager may also get a verbal "tip" about the service if they really messed up on pupose to us.
We once had a waiter that it must have been his very first day and we could see him stealing other waitresses tables as soon as the customer came in the door because he just wanted tip money. His service was horrible and we watched him as soon as the people left he was like a hawk pouncing on the table for the tip money. We could hardly find the guy during our meal when we needed anything, and the main time we saw him was right after he snagged us to get our table. The funny thing was we were about to mention something to the manager about him, and all the other waitresses had pulled the manager aside and we could see they were talking about the "new guy". So they already knew what he was up to, and then we saw the manager ask to speak with him in the back. So we didnt have to complain afterall because the waitresses did for us.