I did the same thing when I waited tables. I never could understand how some of the regulars could come in 2-3 times a week, month after month, year after year and just never, ever tip any of us. We always groaned when they came in, and looked to see which one of us had the misfortune of waiting on them. Then there were other regulars that we fell all over each other trying to be the one that got the privilege of waiting on them.

And I, too, would go above and beyond for the good tippers. Non-tippers got basic service, after I learned that they were non-tippers. If I had a table of good tippers, and a table of non-tippers, the good tippers were getting their drinks refilled first, and checked on more often, etc. And it was fun waiting on regulars who were good tippers. You chat with them, learn about them, you know what they like and don't like, it was a great experience all around. Non-tippers? Not so much. We just wanted to tell them stay home and cook their own food, or go to McDonalds.
I can't imagine that woman being banned from a restaurant for not tipping though, there has to be more to the story. She must have been an all around pain in the butt with the hostess and cooks as well, and not just the servers.